The most dangerous of all sea creatures, they'll either eat you, send cartilaginous, toothy shrapnel through your vital organs, or just bite off your arm and then blow you up. Nobody knows what evolutionary advantage is attained by exploding when angry, but it sure does hurt.
An evil bunny that was created in a physics class, trained to kill any one the creators hated, later other humans got involed with the man eating bunny bringing guns with them shooting anything and realsing the bunny to feed off the dead. Later a whole fictional story was created for man eating bunny.