The cruph

A cruph is a magical type of fish that is mainly brown. Its dorsal fin is webbed and green along with its other fins. It eats meat and sucks algae off of rocks. They have small sharp teeth that can eventually naw through anything. They can spit poison that can paralyze and poison the victim which they then eat the flesh of. Their weaknesses are fire or a large electric shock or shallow water or any other common fish weakness.