Cyberdemon/Doom II RPG

The Cyberdemon is a boss of Doom II RPG. In this game has two bionic legs, one cannon arm, and flesh arm.

It can be taken out fairly easy with the Soul Cube.

Behind the scenes
The Cyberdemon is depicted with two bionic legs in this game, due to a limitation of the game's animation system--each character's legs are required to be symmetrical in design, as the leg sprites (which are separate from the torso and head sprites) are simply mirrored horizontally to create the full set of animation frames for walking. Although artwork was created depicting the Cyberdemon with one "normal" leg and one bionic leg, it was not used in the final game for this reason.