Buttface

Buttface is a land-based creature created off-camera by the Maxis team and shown in the GDC 2005 video. Buttface has six feet, but only three limbs originating from its torso. Each limb - two at the front and one at the rear - splits into two shorter limbs. It has thirteen joints in total.

Will Wright comments: "He has a rather non-standard leg configuration. ... One little kind of subtle trick we're playing with here is that people have never seen Buttface before, so they don't know how he's supposed to move, as opposed to humans."