Ok, maybe mermaids aren't fish, but that's beside the point. What matters is this shark has needs and that need is to eat everything. Other fish aren't enough. Swimmers aren't enough. He needs to eat things like fire, and police cars. If only there was an octopus witch who could grant him his wish (and probably take away his teeth as a condition!).
Basically, Fox's Animation Domination High-Def does it again.