Razor-Toothed Franticant

Etymology
The name is quite simple, in that "Razor-Toothed" does indeed describe the powerful jaws of the franticant. The word "Franticant" itself is a sort of tongue-in-cheek portmanteau of "frantic" and "can't." The animal will go into a state of utter frenzy when feeling even the least little bit threatened, but at any other time it is so docile it barely even moves.

History
The Razor-Toothed Franticant was domesticated as a hunting-fish countless years ago. It actually answers to the call of its master, though this ability is barely understood by modern science. Domesticated Franticants are kept in specialized tanks built of several-inches thick plexiglass, or suitable substitute, to contain the occasional frenzied movements of the being.

Dangers
As it's name implies, the Razor-Toothed Franticant has razor-sharp teeth on both its upper and lower jaws. It has two rows of teeth on the bottom and three rows on the top. These teeth retract into the jaws of the creature while calm or not eating. Once hungry, or once startled, though, the Franticant will bear all its teeth and mercilessly attack whatever it deems a threat.