Its been a bit, may as well dump some more art.
Lunacy is a rather versatile AI life-form, with more than one chassis in his possession. The one he prefers would be his more draconic one, the drake chassis. How else is he supposed to bully those smaller than him without it?
Intended for underwater search-and-rescue, this chassis also sports fins. After being reassigned elsewhere, he likely decided that he felt best with them still.