go into super melee and choose a melnorme ship then fight with the ai. you will see the melnorme cockpit in the usual place. fly your ship around and youll see melnorme's limbs which should clear it up
It really dosen't show any limbs. You see his "shoulders" dip every time you execute a turning command, thrusting, or using the special weapon. a light on his panel glows corespondingly and when he uses his main weapon the bridge turns colors and his face gets a strained look, like he ate way too much cheese earlier that day or something.