Vampire Fish

According to the Croc (Game Boy Color) manual, the Vampire Fish is "A mean fish that snaps his jaws at Croc, be careful of his very sharp teeth!"

In Original Game
These fish appear a couple times in underwater stages of the original game. They are recognizable by their green bodies and red eyes. They swim in predetermined routes, but if Croc gets too close, they will attempt to bite him.

In GBC
These act as obstacles, swimming back and forth. If Croc centers their line of vision, they will charge at him repeatedly. Croc will take damage if he touches one.

Croc: Legend of the Gobbos

 * The Deadly Tank of Neptuna

Croc (Game Boy Color)

 * Desert 3

Trivia

 * The sound effect for the Vampire Fish's bite in the original game is the same sound effect used in Croc 2 for Venus Fly Von-Trappe's bite.