Skitter Chatter may very well be mistransformed on the checklist, however I feel these joints might have a different function. The waist joint can raise and lower so the mouth can open and close as well as give the legs more clearance. The front teeth joint could exist to help line up the teeth. Mine came with the teeth sticking out like this and noting lined up. Also gives the legs more clearance like the waist. That said, teeth dress mode is a thing and I kind of love it. Anyways, Primal and Megatron are having a movie night.