Let's talk about mantis shrimp, aka badass motherfuckers.

Called "sea locusts" by ancient Assyrians, and now sometimes referred to as "thumb splitters" by modern divers — because of the relative ease the creature has in mutilating small appendages — mantis shrimp sport powerful claws, formed like jackknives, that they use to attack and kill prey by spearing, stunning or dismemberment. Some pet mantis shrimp have managed to break through their double-paned aquarium glass with a single strike from this weapon.

Around 400 species of mantis shrimp have currently been described worldwide, which are commonly separated into two distinct groups determined by the manner of claws they possess:

• Spearers are armed with spiny appendages topped with barbed tips, used to stab and snag prey and some have a blunt, calcified club on the elbow.
• Smashers, on the other hand, possess a much more developed club and a more rudimentary spear (which is nevertheless quite sharp and still used in fights between their own kind); the club is used to bludgeon and smash their meals apart. The inner aspect of the dactyl (the terminal portion of the appendage) can also possess a sharp edge, with which the animal can cut prey while it swims.

Both types strike by rapidly unfolding and swinging their raptorial claws at the prey, and are capable of inflicting serious damage on victims significantly greater in size than themselves. In smashers, these two weapons are employed with blinding quickness, with an acceleration of 10,400 g and speeds of 23 m/s from a standing start. Because they strike so rapidly, they generate cavitation bubbles between the appendage and the striking surface. The collapse of these cavitation bubbles produce measurable forces on their prey in addition to the instantaneous forces of 1,500 N that are caused by the impact of the appendage against the striking surface, which means that the prey is hit twice by a single strike; first by the claw and then by the even bigger force from the collapsing cavitation bubbles that immediately follows. Even if the initial strike misses the prey, the resulting shock wave can be enough to kill or stun the prey.

The snap can also produce sonoluminescence from the collapsing bubble. This will produce a very small amount of light and high temperatures in the range of several thousand kelvin within the collapsing bubble, although both the light and high temperatures are too weak and short-lived to be detected without advanced scientific equipment.

Mantis shrimp appear to be highly intelligent, are long-lived and exhibit complex behavior, such as ritualized fighting. Scientists have discovered that some species use fluorescent patterns on their bodies for signaling with their own and maybe even other species, expanding their range of behavioral signals. They can learn and remember well, and are able to recognize individual neighbors with whom they frequently interact. They can recognize them by visual signs and even by individual smell. Many have developed a complex social behavior to defend their space from rivals. [link]

   

Man, am I glad these things live at the bottom of the sea and aren't scuttling around Central Park. I'd hate to come across one in a dark alley.