Darwinning: Mantis Shrimp
Mantis Shrimp are marine crustaceans, which grow up to a foot long and are ferocious enough to have earned the nickname “thumb splitters”.
They have the most complex eyes in the animal kingdom, with 16 different types of photoreceptors. This allows to pick up on infinitesimally minor changes in light refraction, letting them notice transparent prey invisible to the human eye.
One of few crustaceans which actively hunt, their claws are adapted to kill prey as quickly as possible, and can move at the same speed as a bullet being shot from a revolver. This extreme movement in still water is so powerful that the shock wave alone is enough to kill small prey.
Some make their homes in coral skeletons, and occasionally find themselves in aquariums when the coral is used as tank decoration. In such an event, shrimp protocol is to eat every living thing in the area, and smash through the glass.