River Monsters Full Episode - Killer Weapons

Added: 2026-06-04

[00:00:05]In the battle for survival, it pays to be wellarmed. And freshwater fish, in particular, have perfected a spectacular array of murderous hardware.

[00:00:15]Many of the monsters I pursue in dark and murky river water are armed with deadly teeth, spines, or poison. But some pack weaponry I didn't expect.

[00:00:28]I've investigated legends of a monster said to crush its victims with its tongue alone, which turned out to be more like a ballistic missile.

[00:00:40]Sometimes the only way to uncover the truth about killer weapons is to put myself in the front line.

[00:00:49]It's not often I come across a fish I've never heard of, but in Argentina, this is exactly what I faced.

[00:00:56]A fish whose killer weapon is said to melt flesh.

[00:01:05]In the frontier town of Bea Vista, a fisherman tells me the story of a young boy.

[00:01:17]He was playing in the nearby river just a few yards from his mother.

[00:01:23]Suddenly, and without warning, something struck him.

[00:01:28]The fisherman says it happened so quickly that the boy's mother had no time to react.

[00:01:34]The boy died very shortly afterwards.

[00:01:38]I'm told the killer is massive with the appearance of a stealth bomber.

[00:01:45]It sounds like a freshwater stingray, but I've never heard of the ray he describes.

[00:01:52]The barbed tails of stingrays can cause almost instant death if they puncture an artery or vital organ.

[00:02:02]>> But I learn of another case that suggests the killer in this river has an extra invisible weapon.

[00:02:15]A 12year-old girl was struck only yards from the riverbank.

[00:02:21]But unlike the boy, she died a very slow, painful death over several days.

[00:02:31]She didn't die from blood loss alone.

[00:02:34]So why did she die in such terrible pain?

[00:02:40]Perhaps the only thing worse for relatives forced to deal with the aftermath of such an incident would be to live on ignorant about its cause.

[00:02:50]My mission is to uncover the truth about this stingray and find out what kind of weapon could cause such an agonizing protracted death.

[00:03:00]That's easier said than done. It's known that saltwater stingrays have a highly developed sensory system that they use to find and target prey.

[00:03:12]It's possible these sensors could also detect my wire leader and hook.

[00:03:17]So, by changing to finer gear, I might fool the ray into taking my bait.

[00:03:23]I'm going to scale down.

[00:03:26]And uh that's just a bit finer.

[00:03:35]But scaling down isn't getting through this creature's defenses, and even slight downsizing can cause problems.

[00:03:50]In Thailand, I hooked a fish so big it felt like I was trying to pull a gigantic plug out of the river bottom.

[00:04:00]>> It's spinning the boat. It's taking the boat down. Come on. Okay. Okay.

[00:04:04]>> But after a 2-hour battle, my opportunity to land it blew up in my face.

[00:04:13]Losing what to this day could be the biggest fish I've ever had on my line >> still hurts.

[00:04:25]>> There we go. That's a fish. That's a fish.

[00:04:27]>> In Argentina, I'm now dealing with the same problem. Prying this monster out of its bunker.

[00:04:38]But I'm not going to let history repeat itself.

[00:04:46]Oh yes, it's coming. CL is here. To the surface.

[00:04:56]Surface. There it is.

[00:04:59]Finally, I have one of the most alien freshwater fish I've ever seen. Right where I want it.

[00:05:07]>> It's off the bottom, but there's trees down here.

[00:05:12]This is a short-tailed Argentinian stingray.

[00:05:18]I don't want to bring this potentially deadly fish into the boat, so I asked the skipper to head for the nearest beach.

[00:05:25]>> Was that more tranquil?

[00:05:30]>> I put on knife proof Kevlar gloves to protect me against the barb >> and just pull it up.

[00:05:36]>> As soon as it's out of the water, its tail is aiming for me.

[00:05:44]This flailing tail is not only armed with spikes, it's got another deadly weapon, too.

[00:05:52]>> Want to see if I can get a a look at that.

[00:05:58]>> A local doctor told me that the entire skin of this alien creature produces necrotic venom that becomes more concentrated around the tail and along the barb.

[00:06:10]It's covered in slippery mucus, loaded with flesh rotting venom.

[00:06:15]>> Just going to see if I can get any uh mucus off here.

[00:06:18]>> The venom is what most likely caused the 12-year-old girl's awful protracted death.

[00:06:25]Once the barb pierces skin, the toxins are injected, which rapidly destroy the surrounding flesh, and there's no known antidote.

[00:06:35]It's what converts a primitive spike into a hideous chemical weapon.

[00:06:42]>> That's actually one heavy beast. A weapon like that with four, five, maybe 600 lb behind it, you know? It's like somebody coming at you with a medieval mace in a way. It's like a club with a nail in it. Anyway, let's get it back.

[00:06:56]A camouflaged predator with a doublebarreled means of assault.

[00:07:02]Despite the deadly potential of its poisonpacked barb, a stingray only uses this in self-defense when it believes it's being attacked. Other monsters, however, have more sinister intentions.

[00:07:15]And on some rivers, it seems these man-eaters are lurking around every corner.

[00:07:24]On the Fitzroy River in Australia's wild northwest, there were times when I felt more hunted than hunter.

[00:07:32]Just about everything was toolled up for battle.

[00:07:37]Casting a bait in here was like entering the lucky dip from hell.

[00:07:47]Out of the corner of my eye, I'm already aware of sinister company. A saltwater crocodile around 14t long, easily crushing a hardshelled crab.

[00:08:00]It wouldn't be a good place to fall in.

[00:08:02]A beast this size could tear off my leg in one bite.

[00:08:11]>> Yeah, something on there.

[00:08:14]>> I'm hooked into something meaty.

[00:08:20]That's actually running.

[00:08:23]>> Back a little. Back a little. Back.

[00:08:25]Back. Back.

[00:08:25]>> Oh, here we go.

[00:08:27]>> Coming up. Okay. Okay. Hold it there.

[00:08:29]Hold there. Hold there. I'll take this easy cuz I can't actually I can't get a positive ID in the water. It's very muddy water.

[00:08:37]Whatever it is, I'm betting it's going to be heavily armed.

[00:08:47]There we go. That is a bull shark.

[00:08:49]>> I keep well clear of its mouth. Even a 5ft juvenile could bite my hand off.

[00:08:56]Take it off. Adults can reach double this length, as I know from personal experience.

[00:09:03]>> These fish probably kill more people than any other.

[00:09:07]>> I've caught monsterized bull sharks like this one from a river.

[00:09:14]But what few people realize is how far into fresh water they'll go in search of prey.

[00:09:22]Over in the east of Australia in the summer of 2002, a 23-year-old student and his friend head for a cooling swim in Miami Lake.

[00:09:38]This lake is around 12 mi from the sea, and they believe they're swimming in safe water.

[00:09:48]One man heads into a deeper part of the lake.

[00:09:55]In an instant, he's gone.

[00:09:59]His sudden disappearance had all the hallmarks of a shark attack.

[00:10:06]But few could imagine this apparently safe backwater to be a hunting ground for sharks.

[00:10:14]The autopsy revealed that he had been struck three times by a bull shark.

[00:10:20]One devastating bite through his left thigh, proving fatal.

[00:10:29]The thigh is the fleshiest area on the human body and the most common part for sharks to hit.

[00:10:37]Marine scientist Vic Pedomores explains how a bull shark wields its weaponry so effectively.

[00:10:44]It's a very robust animal, very rough and tough. Because of the structure of its teeth, it can't just bite through a big chunk of meat. It has to bite and start shaking like crazy. And of course, somebody's like a rag doll in its mouth getting thrown all over.

[00:11:05]Operating like a sub loaded with sophisticated sensors, this predator had slipped into fresh water with ease.

[00:11:13]And once it reached the lake where the men went swimming, it could move about freely, completely unseen until when it attacked, its savage brutality was revealed.

[00:11:30]This bull shark is around half the likely length of the one that killed the student, but it's still potentially dangerous to anyone swimming in the wrong place at the wrong time.

[00:11:41]It's a muscular brute toolled up for this underwater battle zone.

[00:11:52]>> That's a bit of drama. I'm glad we got that in.

[00:11:55]>> But in some ways, I'm just as glad to see it go.

[00:12:01]A bull shark's teeth are at the sharp end of its lethal capability to kill, but how it uses them is really unusual.

[00:12:09]The upper jaw isn't attached to the skull, so it can push its teeth forward, increasing the area of attack to rip off superized chunks.

[00:12:18]When it isn't feeding, the bull shark's teeth remain hidden. But one of its cousins keeps its weapon permanently on display.

[00:12:27]A 100 million years ago, a creature with a head like a chainsaw patrolled its underwater layer in salt and fresh water. Today, it still does.

[00:12:39]Sawfish wield a weapon that can measure 6 foot in length decorated with viciousl looking 2-in long knives.

[00:12:48]And when this chainsaw-like weapon has an ultra high-tech motion detecting device, it becomes a truly menacing prospect.

[00:13:01]Giants over 20 ft long have occasionally been caught, and legend has it that these monsters will even attack boats.

[00:13:11]A newspaper article from the 1930s describes an attack off the coast of Florida. The story goes that a fisherman harpooned a large sawfish in shallow water.

[00:13:23]But when the brute spun round and struck the boat with its snout, the tables were suddenly turned.

[00:13:39]>> I shudder to imagine that rack of teeth sthing into human flesh.

[00:13:50]Sawfish are now extremely hard to track down anywhere in the world.

[00:13:56]But the Fitzroy River in Australia is reputed to be one of the last hideouts for this freshwater outlaw.

[00:14:05]>> And I've been given permission to take them on.

[00:14:09]I've found allies in the Aboriginal tribes people who live alongside the river. There are records of sawfish rostrms being used as weapons right across the western Pacific from the Philippines down through New Guinea as far as New Zealand. They'd use it to slice open the abdomen of their enemies and also to open up the veins on the inside of the elbows causing fatal bleeding.

[00:14:34]If looks alone are anything to go by, this is evidently one fish I need to treat with respect.

[00:14:41]Sawfish are nocturnal. They hunt in the dark.

[00:14:46]Tonight, I hope to corner one of these ferocious looking predators in fresh water and get a close-up look at how it uses its weapon.

[00:15:06]Oh, fish on. Fish on.

[00:15:11]Yeah. Yeah. Yeah. Yeah. Yeah.

[00:15:18]Good size. Good size.

[00:15:24]It's coming in quite close. It's already quite on the rocks in here. I need going to need someone to grab it.

[00:15:32]I think it's ready. It's ready, I think.

[00:15:36]Oh, it's a sawfish. It's a sawfish.

[00:15:51]Look at this for a beast. This thing's nearly 7 foot long. That's bigger than I am. And that rostrm on there, that's a foot and a half long. It's got 39 of those teeth. Each one is about an inch long. Wickedly sharp. The rostrm also has a series of pores running along its length that can sense the smallest movement, including some say the heartbeat of prey.

[00:16:16]This detection system triggers a flailing action to slice its victims into pieces before it consumes them.

[00:16:26]And when the body flexes, it's this head and this rostrm that really sighthe from side to side.

[00:16:33]>> Here we go. Yeah, >> I came here to find out if this fish is also a monster in terms of deed. Now, there's no doubt that that fearsome tooththed rostrm is potentially a lethal weapon, and it's certainly been used as such in the hands of humans, but I can find just no instance at all of this fish having attacked a human being willfully.

[00:17:01]Even so, just by looking at it, you can tell this is a fish you don't want to get in the way of.

[00:17:09]Other deadly fish, however, look harmless. One Amazonian monster keeps its weapon hidden and does its hideous damage out of sight.

[00:17:18]This is the kangaroo assume, a nondescript fish just the size of a finger, which drills a clean, bullet-sized hole into its victim's body.

[00:17:31]Then with its sharp teeth, it spins its way deeper inside, feeding on the organs as it goes.

[00:17:41]Scientist Dr. Lucia Rap has examined some of the resulting corpses.

[00:17:46]>> The corpse were hollowed already inside without any organs.

[00:17:50]>> Wow. I'm just trying to imagine being a pathologist and you're brought a corpse.

[00:17:54]There's what looks like bullet holes.

[00:17:57]You start to dissect the body and the body is hollow. The organs have been removed >> and there was any kind of bullet or something inside the corpus, just the fishes. So he realized that the fishes got inside the bodies and eaten the organs inside.

[00:18:13]>> Disturbingly, the attacks might have happened while the victims were still alive, though hopefully unconscious.

[00:18:19]>> These fish are purposebuilt for the for the task, it appears. Cylindrical body, very smooth and slimy.

[00:18:26]And then they have this mouth that when it opens, it produces a circular bite.

[00:18:33]Such weaponry gives this monster a ghoulish advantage over its victims.

[00:18:39]7,000 m away from the home of those pocket-sized assassins, I heard there was another creature using a similar technique. But this serpentine fish was said to grow 10 times the length of the kandaru sue.

[00:18:55]In New Zealand, a man called a radio show that I appeared on to tell me the horrific things he'd seen.

[00:19:05]>> Before they could get out, these eels were attacking them from behind and going in the back passage of the sheep.

[00:19:12]Giant long fin eels were said to have entered through the orififices of sheep then eaten them alive from the inside measure until they were pulling the intestines out and going right inside the animal and getting right up to the to the liver and that before it actually ceased to live.

[00:19:34]There are also reports that these creatures are bold enough to attack people and strike with enough force to break ribs.

[00:19:50]To get to the bottom of what they're capable of, I head to a remote river in the south of New Zealand.

[00:19:59]Here in the heart of primeval wilderness, I'm told I'll find wild eels, giving me the chance to see just how aggressive they can be.

[00:20:13]To draw them in, I first soak my clothes with fish guts. Put simply, I'm turning myself into human bait. I can feel my heart starting to pound. This has to be one of the scariest things I've done.

[00:20:28]I'm wearing cutproof gloves and a full wet suit to protect me from the eel's needle sharp teeth.

[00:20:51]In seconds, they arrive.

[00:20:56]Around 30 giant long fin eels, and they're completely fearless.

[00:21:02]They're catching the whiff of blood and moving in. Some nearly 5t long and thicker than my arm.

[00:21:10]That is just so snake like coming out of the water with his mouth like that.

[00:21:15]>> What I don't want is them to draw blood.

[00:21:16]If they draw blood, that could really get them going. I'm hoping they're going for my hands, but they seem to be interested in other parts, which is a bit disconcerting.

[00:21:24]And even if I move, if I move my legs, I move my hands, it's not really sending them away at all.

[00:21:32]>> In fact, quite the opposite.

[00:21:35]>> They're right. They're coming right in close.

[00:21:39]The thing about these fish, these are not fish that people feed. These are wild fish. So, they are hungry. They're bumping my legs. They're taking up my shirt and they're coming in on my fingers as well.

[00:21:52]I do want to hold my ground. I mean, I've come this far. I don't want to get out too too quickly.

[00:21:57]>> Get out. I need kevlar underpants as well. Most fish would not do this at all. Even piranhas. Ow.

[00:22:03]>> These eels have a three-fold approach to attack. With their backward-facing needle-sharp teeth, >> they clamp onto flesh like a vice.

[00:22:16]Once they're locked on, they can spin their bodies at 700 revolutions per minute. Faster than a cordless screwdriver.

[00:22:24]Ow.

[00:22:25]>> Combine these with a fearless attitude and you get a top level predator.

[00:22:30]>> That was inside of the thigh.

[00:22:32]>> They seem to be looking for an easy way in.

[00:22:34]>> That is one aggressive fish.

[00:22:37]>> The idea that an eel of this size could worm its way inside a living sheep is disturbing enough.

[00:22:46]But now that I know how that's possible, I'm really creeped out.

[00:22:53]>> Look at that. Look at that. Look at that. Look at that. LOOK AT THAT.

[00:22:56]>> I think it's time for me to get out. Get out. Get out.

[00:23:02]Only full body armor would give complete protection from those fish. But there's one creature against which even this would be useless, for it possesses a weapon unlike any other.

[00:23:16]In Brazil, I heard of a deeply chilling incident, but one with tantalizingly little evidence.

[00:23:31]>> A horseman named Heinaldo tells me how a mule had become stuck in the water.

[00:23:39]>> With the help of five other cowboys, he tried to rescue it.

[00:23:43]What they had to do was actually sort of go in and just try and pull the animal out.

[00:23:52]The first three cowboys went into the water. Heardaldo and the others hung back.

[00:24:02]As the first horses got up to their bellies, something startled them.

[00:24:18]asaldo escaped only because he'd hung back.

[00:24:26]>> People who fell in the water actually disappeared. And we're talking water that was um it sounds like 3 or 4 feet deep.

[00:24:34]>> He gives me the name of his prime suspect.

[00:24:38]be nice shade.

[00:24:39]>> It's a creature I've heard about but never encountered. With a weapon so potent, it can execute three full grown men.

[00:24:52]After 10 days of searching for the suspected killer, finally I'm zeroing in on its lair.

[00:24:59]This is said to be the home of an electric eel, a creature with the power to stop a human heart.

[00:25:07]But the beast is in a place I'd never expect. A mud puddle in the middle of a farmer's field.

[00:25:14]>> Does that look like just one of these one of these branches? One of these roots. That is an electric eel. It's a big one. This fish comes armed with a devastating taser-like weapon.

[00:25:26]It'll keep firing until it knows its victim's heart has stopped pumping.

[00:25:32]A technique it uses both for self-defense and attack.

[00:25:39]Having an advanced plan for getting my hands on it is crucial. I've got no desire to be electrocuted.

[00:25:45]>> I'm just making a bit of a trench from my point of view. It'll be easier to handle if there's some kind of sort of notch that it's in rather than it being able to slip and slide all over the place.

[00:25:57]My normal capture method would be pointless in water this shallow. So, out goes the rod and in comes a lasso.

[00:26:04]Fitting for cowboy country.

[00:26:08]Nearly 3/4 of this fish's body is used to generate electricity.

[00:26:14]Protective clothing is essential.

[00:26:19]We've got a plan. The plan is not so much to to sort of go after the head with the noose, but to position that and then get it to go through the noose.

[00:26:30]Just taking a few deep breaths because one slip and you know it could be very nasty indeed. need to be so focused and so careful about this.

[00:26:44]An eel this size could deliver a shock of 650 volts. That's enough to stop my heart in seconds.

[00:27:02]First go. Amazing. First go.

[00:27:10]>> Electric eels can keep on shocking out of water. If we weren't wearing rubber gloves, we could be dead.

[00:27:17]>> That is like it's doing a sort of It looks like a muscle contraction spasm almost. That's when it's actually shocking.

[00:27:27]That's 5' 10 and a half. That's pretty much exactly the same as as me.

[00:27:34]>> An eel this size is capable of producing a high enough voltage to kill one of the cowboys.

[00:27:43]But could one fish have killed all three?

[00:28:00]Suddenly, out of the corner of my eye, I glimpse more movement.

[00:28:05]>> There's more. There's more. There's more. Again, it looks like wood, but it started moving. We were watching it, and it looks like there's actually several, but smaller right in with these roots here.

[00:28:19]>> It's a writhing mass of electric eels.

[00:28:22]>> It's like a tangle of bodies. But I'm just trying to count the heads.

[00:28:27]The more I look, the more I see. I was thinking 10 or a dozen. I think there could be 20 down here.

[00:28:33]This is an incredible discovery and could answer the final question about how the cowboys died.

[00:28:44]Each one of these fish could deliver a fatal shock.

[00:28:49]So, a group of 20 would easily be capable of killing the cowboys.

[00:29:03]Electric eels have highly evolved hidden weaponry, perfectly designed for a muddy environment.

[00:29:09]But there's one river monster that carries weapons honed over millions of years, together with a reputation for extreme violence.

[00:29:19]This armor-plated dinosaur stands accused of savage attacks on people across the deep south.

[00:29:28]I was on a mission to find out if this monster's reality matched its ugly myth.

[00:29:34]I'd heard tales of a violent attack in Louisiana.

[00:29:44]I catch me.

[00:29:47]>> On a warm, humid spring day, a 9-year-old school girl and her 13-year-old brother are playing on the shoreline of the lake.

[00:29:55]>> Oh, darn it. You would >> The girl dangles her feet in the water.

[00:30:12]>> Always win. you always do.

[00:30:20]>> Suddenly, something grabs hold of her leg.

[00:30:30]The boy drags his bleeding sister to the nearest clinic.

[00:30:36]Dr. Robert B. Payne, though a physician for almost 40 years, has never seen wounds like this.

[00:30:45]How big was it?

[00:30:46]>> The boy claims that what attacked his sister was 7 foot long and he believes it to be a fish called an alligator gar.

[00:30:55]Locals tell me that even today they've seen them double that length.

[00:30:59]>> Now I have seen one 14t long down there.

[00:31:03]>> It's no wonder that people took fright when you consider a beast of those dimensions with a couple of hundred razor sharp teeth.

[00:31:11]As I head out on the Trinity River in Texas, home to these fearsome fish, I'm aware that only my rod and line stands between me and potential attack. He's got it.

[00:31:22]>> It's moving. It's moving right to left.

[00:31:25]>> I need to let the line run very freely to avoid the fish realizing the bait's attached to anything.

[00:31:30]>> It's a bit of a battle of nerves this.

[00:31:32]Something's taken off. It's on the end.

[00:31:41]Oh, I think it's off.

[00:31:43]>> Oh, no. No, no, no, no.

[00:31:44]>> It's coming toward us.

[00:31:48]>> That's a small It's a turtle or is a small fish? It's coming.

[00:31:52]>> Is it a needlenose?

[00:31:55]>> This alligator gar is just 3 ft long, giving me an ideal opportunity to safely examine its weaponry.

[00:32:04]Right, these fish grow 18 in in their first year. This one's around 1 to two years old.

[00:32:11]It has two rows of teeth along the upper jaw.

[00:32:15]These teeth are 38 of an inch long, a quarter the length of those on a fully grown gator gar.

[00:32:29]>> Oh my god, you got bit, huh?

[00:32:30]>> I was just in there trying to get the the hook out.

[00:32:32]>> Score one for the fish. Yeah, that's a very young alligator guy with a big appetite. Uh, I'm just going to lob him back in the water. Whoops.

[00:32:41]Back in the water.

[00:32:45]Maybe it does deserve its reputation after all.

[00:32:51]Okay, this fish is actually still got a lot of energy left. I I brought it in on very heavy gear, so it's actually got a lot of energy left. Normally, they'd be pretty tired out. I think I'm just going to slide him over the side. Uh well ahead of our next fishing spot. So here we go. Back you go.

[00:33:06]>> Even a fish as small as this has managed to draw blood.

[00:33:10]>> Good battle ski, didn't it? But you can see the sort of the the cut on it.

[00:33:16]>> The consequences if this fish was scaled up to a monstrous 7 to 10 ft are beginning to hit home.

[00:33:30]When you think about a gar that size with teeth to match and a body like a torpedo, it really is a terrifying prospect, you've just got a living weapon of destruction.

[00:33:47]Now I need to find one of that size to see if they're truly capable of deliberate attacks on people.

[00:33:59]That was definitely a fish moving off.

[00:34:01]>> Mhm. For sure.

[00:34:04]>> Not a damn thing.

[00:34:08]>> This is It's actually very, very frustrating fishing. I mean, something definitely had that in its mouth cuz it moved at several yards. But when I tightened down, there's nothing there.

[00:34:17]>> But focused on my target, I fish on >> towards dusk.

[00:34:21]>> What do you reckon? Tighten down.

[00:34:25]>> Right.

[00:34:26]Normally gar are caught before the water begins to cool down. Well before the sun sets.

[00:34:33]>> Let's go up. It's gone up again.

[00:34:35]>> Most people give up fishing by midafter afternoon.

[00:34:41]Set it. Set it. Set it. Set it.

[00:34:43]>> Yeah. Yeah. Yeah. Yeah. That's a fish. I can't tell.

[00:34:49]Yes.

[00:34:51]Yes.

[00:34:54]Oh, it's gone under the boat. Under the boat. Under the boat. Under the boat.

[00:34:56]>> Keep the tip away.

[00:34:58]>> That soaked me. I'm here 4 ft above the water. I got a splashing.

[00:35:02]>> Finally, it seems I'm going to get face to face with this heavily armed river monster.

[00:35:07]>> Okay, it's pulling down. It's pulling down.

[00:35:10]>> Look at that. Look at that rod, too.

[00:35:12]>> Let's get him off. Let's get him off.

[00:35:13]>> After fishing for 12 hours straight, I set my eyes on the giant fish.

[00:35:19]>> Yes.

[00:35:21]Do you want me to?

[00:35:23]The most dangerous part of gar fishing is bringing the fish aboard the boat.

[00:35:30]>> As the gar comes aboard, it thrashes its snout from side to side like a sythe.

[00:35:36]I haven't forgotten that three-footer that got me.

[00:35:39]>> This will go.

[00:35:40]>> And this fish is more than double the length of that one. Okay.

[00:35:45]>> The teeth of this scar are another half inch longer than those that scarred me earlier.

[00:35:53]Think it's 123.23 lb.

[00:35:57]>> Good, good, good, good.

[00:35:59]>> Yes.

[00:35:59]>> Finally getting my hands on the fish and seeing it face to face, I can begin to weigh up the evidence. Is this beast really as deadly as people say?

[00:36:08]>> Actually, laying hands on this prehistoric beast. This is fantastic. I mean, this is the creature that I came here to to see. Then once again, the gar draws blood.

[00:36:23]Put that in there.

[00:36:25]>> I've been cut by this monster's armor.

[00:36:28]Very hard to hold. That is the back of a scale or some scales. The points of the rear points of these triangular scales stuck in. The Native Americans used to use them as arrow heads. And I can sort of see why now.

[00:36:41]>> But this wounding was accidental. This fish has no intent to deliberately harm me.

[00:36:47]Gar don't bite pieces off their prey.

[00:36:51]They only eat what they can swallow whole. And that takes humans off the menu. For all this fierce reputation, you know, they do seem to be, you know, they certainly look the part, but I'm not sure that they actually act up to the part.

[00:37:07]Oh, what a thing. What an animal.

[00:37:10]This gator gar seems too gentle naturatured to cause deliberate harm.

[00:37:16]I believe I've seen enough to clear the gar's name.

[00:37:19]>> Not easy. Not easy. Not easy.

[00:37:22]>> Okay, >> it's time to return this one to the wild.

[00:37:26]>> There it goes. There he goes.

[00:37:28]>> Excellent.

[00:37:29]>> Wow.

[00:37:34]>> This experience gives me the confidence to take the next step. I'm going to dive into the alligator gar world without protection to prove my theory that this fish is a monster only in looks and not indeed.

[00:38:09]These fish have no interest in harming me.

[00:38:14]The alligator gar has been persecuted for many decades because of the way it looks.

[00:38:21]Their resulting decline in many states of the US is now a cause for serious concern.

[00:38:31]Oh, that was that that was that was an experience. Oh, I have to say the size the size and the aspect of those fish though when I first saw them was really quite intimidating. But I think this is a very very misunderstood animal and I think it really is time that we just try to understand this fish a little bit better.

[00:38:57]While alligator gar have been wiped out of many rivers and lakes, other fish are taking advantage of the opportunity to move into new habitats and wreak havoc.

[00:39:07]These river monsters don't seem to care where their battlefield is.

[00:39:14]In the far reaches of Papu New Guinea, I was determined to track down one such monster that launches full frontal assaults in a way that I personally find terrifying.

[00:39:28]To this day, just the thought of it still brings me out in a cold sweat.

[00:39:41]>> Villagers here told me Patrick Mo was bathing in the Seik River directly in front of his house when the creature struck.

[00:39:56][ __ ] >> He was hit by a powerful solitary hunter.

[00:40:03]Mo had the most sensitive parts of his body bitten into and then bitten off.

[00:40:10]According to reports, blood loss was so extreme he bled to death.

[00:40:17]>> The attacker has been branded the ball cutter.

[00:40:22]None of the native fish species would be capable of inflicting such horrific injuries.

[00:40:29]As I draw up a list of potential suspects, my mind turns to fish I've hunted down in other rivers.

[00:40:36]I wonder whether one of these might be capable of this attack.

[00:40:42]>> Fish on.

[00:40:46]A vampire fish has teeth so long and so sharp, it could cause serious mutilation.

[00:40:54]Piranhas compensate for lack of size by attacking on mass.

[00:41:01]They have the weaponry, but the attacker here is a solitary hunter.

[00:41:06]And crucially, both these fish are native to South America, half a world away.

[00:41:13]Neither has been seen in this river.

[00:41:17]The culprit must be in a different league altogether.

[00:41:22]A castrating killer, an outsider, and one with no known identity.

[00:41:33]I struggle to hunt down the perpetrator.

[00:41:38]I'm just not getting any interest at all.

[00:41:46]Blimey.

[00:41:49]>> Strong, strong fish.

[00:41:50]>> But right in front of the village, I get my first bite.

[00:41:55]Looks like a piranha.

[00:42:02]That has got teeth, but they're not piranha teeth. Unless I'm very much mistaken, that looks like a fish that I know from the Amazon called a pu. They are vegetarian. They feed on things like nuts that fall in the water. Looking at the teeth, they're not cutting teeth. They are grinding teeth.

[00:42:23]These fish are however related to piranhas. And a local tells me they've been transported 10,000 m from the Amazon to this river in Papio New Guinea.

[00:42:32]>> Really?

[00:42:33]>> Yeah.

[00:42:33]>> To provide food for local people.

[00:42:40]But since Paku are not meateers, I'm no closer to identifying the killer.

[00:42:47]Then more reports of attacks start to come in. A village woman describes being bitten on the buttocks, leaving deep scars.

[00:42:56]Then I discover an incident nearby that has the same hallmark as previous attacks. And this victim, Nick Sakat, was lucky to survive. I pulled my leg up, but it was coming again and hit my leg.

[00:43:13]It's like human beings teeth biting onto my leg.

[00:43:20]Nick Sakat was fortunate enough to shake the creature free.

[00:43:26]What kind of predator could leave the humanlike teeth marks Nick described?

[00:43:35]Locals are insisting the culprit is the Amazonian invader. The pu hit her teeth.

[00:43:44]>> Back in its home, it's known for using its muscular jaws to crush Brazil nuts that have fallen to the river. Its bite strength, according to some scientists, is 30 times its body weight. Could it be redirecting its weaponry to become the castrating killer?

[00:44:04]To discover whether this vegetarian has turned carnivorous, I'm hunting with meat.

[00:44:10]I need to find one big enough armed with the deadly weapons needed to launch these monstrous attacks.

[00:44:18]Yeah. Yeah. Bigger one. Bigger one.

[00:44:19]Bigger one. There it is. I know there's snags on the bottom, so I'm trying to keep it away from that. Yeah. Just see it. It's black water.

[00:44:27]Just see it down there. Yeah. Yeah.

[00:44:28]Yeah. Oh, yes.

[00:44:31]I'll get it well and sure and tie out before I try and do anything with this one.

[00:44:36]>> But is it wellarmed enough to be a killer?

[00:44:40]>> I'm eager to get a look at the business end. Don't want to rush it.

[00:44:45]This relative of the piranha is compact and dangerous.

[00:44:50]Oh, and that actually just take a look at that as I lifted it out. That straightened the hook as I lifted it out.

[00:45:00]Gosh, very muscular fish. Just gave a bit of a kick there.

[00:45:05]This is all muscle here. So, it's a very strong fish. Very powerful. But, um I'm just Oh, I'm just trying to look at the business end here.

[00:45:15]Those teeth really do look uncannily like human teeth. And to be bitten by those, you know, I think that would be a very creepy experience. It would be just like being bitten by a person.

[00:45:26]I mean, those are real cr real real crushers.

[00:45:31]This thing really does look like a giant piranha, but the teeth on this not designed for cutting, but for crushing and tearing.

[00:45:40]Basically, they're nutcrackers.

[00:45:45]>> The pain from its bite really would be excruciating.

[00:45:49]>> They said that when a piranha bites you, when it actually bites, you don't know what's happening because it's such a clean cut. But this would be a very jagged, messy tear. And I think you'd certainly know about this when this bit you.

[00:46:04]And if these fish hear something splashing in the water, they don't go heading the opposite direction like other fish. They come heading for that sound with those teeth bared.

[00:46:13]I'm left in no doubt that the pu is the bull cutter. A fish that's developed a taste for human flesh with the weaponry to castrate a full-g grown man.

[00:46:26]These fish are clearly adaptable.

[00:46:29]Having taken over this river in Papio New Guinea, they could possibly do the same elsewhere in the world. Isolated individuals have now turned up in over half the US states. And there are recent reports from the US of two attacks on young girls that seem to be the work of this monster.

[00:46:48]When you play with nature, nowhere is safe.

[00:46:52]That's why this predator continues to haunt me.

[00:47:02]>> By investigating stories of attacks on humans, I've uncovered river monsters that are capable of violence beyond many people's imagining. with a range of weapons that seem to defy possibility.

[00:47:17]From sthing sores to electrocutioners, toxic flesh melters and beyond.

[00:47:29]Each creature fighting to survive in the underwater arms race.

[00:47:37]And with all those lakes and rivers in the world, who's to know what other weapons may be down there?

[00:47:46]There's a fish. There's the fish. There it is. There we go. There we go. There we go. There we go.

[00:47:53]That is certainly a big fish.