Bat is an enemy Badnik encountered in Volcano Valley Zone, the fifth level of Sonic 3D: Flickies' Island.
A mechanical bat with a fire-red colour scheme, this Badnik will hover around a fixed area of the level. It has no active defensive or offensive techniques, so the only way this bot can hurt Sonic is if the hedgehog bumps right into it. Attack with a Spin Jump or Spin Attack. Smash it to recover its organic battery power source, a purple Flicky, and make Flickies' Island a slightly less dangerous place.
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.