Pengo is an enemy Badnik encountered in Diamond Dust Zone, the fourth level of Sonic 3D: Flickies' Island.
Amongst the more realistic-looking of Robotnik's criminal travesties of nature, this Badnik simply waddles back and forth along a straight diagonal. It can only harm Sonic if the hedgehog walks straight into it; smash it with a Spin Dash or jump to recover its organic battery power source, a green Flicky, and make Flickies' Island a slightly less dangerous place.
This Badnik is part of a long line of penguin mechas, including:
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.