Sharks might be the best-designed killing machines that exist in the natural world. They spend the bulk of their lives hunting and viciously killing smaller animals to satisfy their enormous energy needs. In short, sharks are big, mean, and scary. However, the laws of nature don’t make special exceptions based on taxonomic classification. As it turns out, just calling yourself a shark isn’t enough to guarantee that no other ocean dweller is willing to take a swing at you.

The ocean is a dangerous place. In the rare situations that sharks aren’t the biggest, meanest, and scariest creatures swimming around, they too can find themselves on the wrong end of a set of jaws. Here’s a look at some sea monsters that have proven themselves able to turn the tables on sharks and make a meal out of them. 

1. Octopus

  As far as cephalopods go, giant squids enjoy most of the notoriety. There’s an indelible terrifying quality that being a 40-foot-long, sharp-beaked mass of tentacles imparts that few other sea creatures can match. Still, their smaller cousins have a lot going for them in the “lethal predator” department. Octopuses are among the smartest animals on land or sea, and in the GIF above, you’ll see the price one shark paid for underestimating them. The octopus appears to have been camouflaging itself at the time, and as soon as the shark strayed too close, it pounced. While the shark’s small size made it a less intimidating target than most, this octopus’ 8-armed embrace is clearly a deadly one.

2. Orca

SeaWorld and Free Willy have worked in concert to untether the public perception of orcas from reality. The general sentiment that these monsters occupy the spot next to golden retrievers on the animal friendliness spectrum is misguided, to say the very least. Frequently (and aptly) referred to as “killer whales,” orcas are among the most ruthless killers in the animal kingdom. 

Orcas are both bigger and more intelligent than sharks, and if that weren’t enough, they also have the unique advantage of traveling in packs. The true wolves of the sea, a group of orcas can here be seen dissecting the carcass of a large shark that had the misfortune of crossing paths with them. The group hunting tactics that killer whales display are incredible in their sophistication and ruthless in their execution. Sharks aren’t a preferred prey item for orcas, but when other options are scarce, an unlucky few can find themselves on the menu.

3. Grouper

The appropriately named goliath grouper doesn’t find itself outgunned in the size department very often. The giants can grow to 800 pounds and over 8 feet long, and they eat correspondingly massive prey. This four-foot-long blacktip shark found itself both outsmarted and undersized in late 2014, when a fisherman off the Florida coast hooked it on a live mullet. 

As the angler brought the small shark boatside, a dark mass began to materialize from the deep. Seconds later, an explosion of force rocked the boat as this enormous goliath grouper crushed the vulnerable blacktip. The grouper made off with the shark—or what was left of it—and the fisherman was left with this spectacular video of the topwater strike.

4. Bigger Sharks, Example 1

The open ocean food chain is governed by one overarching rule: bigger is better. Shark or seal, turtle or tuna, whiting or whale shark, an animal’s place in the ecosystem is determined by size. Big sharks are closer to the top of the food chain than little sharks. This means that—you guessed it—big sharks are completely unprincipled about cannibalizing their own kind. 

In the video above, a small, vulnerable blacktip learns the hard way that it’s a shark-eat-shark world. A fully-grown bull shark, somewhere in the neighborhood of 9 feet long, succeeds in swallowing most of the blacktip whole before realizing that it will have to leave a fin or two behind. Bull sharks have a (highly accurate) reputation for being some of the meanest, most aggressive fish in the sea, and they are much less picky about what they eat than other sharks. Apparently, family ties don’t mean much to a bull shark.

5. Bigger Sharks, Example 2

The best evidence that sharks are indiscriminate killers when they’re hungry might be the fear with which small sharks respond to the appearance of a larger predator in their midst. In the excellent drone footage shown above, a massive hammerhead is clearly intent on preying upon a school of smaller blacktips. At first, the small sharks slowly accelerate in an effort to put distance between themselves and the hammerhead. That all changes when the hammerhead hits the gas. Knowing they’re firmly in harm’s way, the blacktips scatter as fast as they can. One nearly does a barrel roll and comes out of the water in its panic. Preparedness—and lots of eyes spotting the hammerhead before it got too close—saved this school from becoming lunch. While this group was fortunate, they were also clearly conditioned to fear the hammerhead. Small sharks know that if they don’t steer clear of their larger relatives, they’ll never get a chance to grow up. 

In spite of all these videos, it’s important to realize that sharks are the dominant predators in their environments a vast majority of the time. They’ve often been described as “perfect killing machines.” The characterization is a fair one. The fossil record indicates that they’ve barely evolved over the past several million years, likely because they don’t have to. They are such successful hunters that it’s hard for nature to improve on the design. However, these videos demonstrate that nothing in the ocean is safe in every situation. Bigger, smarter, and more deadly hunters sometimes do inhabit the same waters as sharks themselves. In the broader marine ecosystem, just being born a shark isn’t enough to keep you out of a hungry mouth.