Fish is an enemy Badnik encountered on Flickies' Island in Sonic 3D: Flickies' Island. It is the only enemy in the game which appears in more than one level; namely Spring Stadium Zone and Gene Gadget Zone.
A hovering puffer-fish reminiscant of the nautical Pointdexter (and their mutual successor Senbon), this Badnik floats back and forth along a fixed diagonal line. It will periodically puff up (extending its spikes) and then deflate; the player must make sure Sonic only attacks with a Spin Jump when it's deflated, otherwise they'll be losing Rings. In Gene Gadget, the floating fish have a tendency to hover above electrified floors, preventing the player from simply standing underneath them and waiting until it's safe to attack. Carefully smash the bot to recover its organic battery power source, a purple Flicky.
The name of this Badnik is conjectural, as no official name has been given to it. The name comes from the level editor in a development build of Sonic 3D that is included as a bonus feature in Sonic 3D: Director's Cut. Jon Burton has confirmed that the name was used in the original game.