Skullfish

These flesh-less fish live in the seas around Great Bay in Majora's Mask. They swim at you and bite you. Dispose of them by putting on your electrical attack as Zora Link.

In Twilight Princess, they appear in Lakebed Temple. It is possible to catch them with your Fishing Rod, and you'll receive a Heart from them, though they won't be stored in your journal due to being an illegal fish.