Design-wise? A torso hanging upside down with the head removed. The neck stump opens up like a flower to reveal the single eye. The hands were once attached—you can see that the wrists end in stumps with the bone partially exposed—but now float freely and are still under Bongo Bongo's control.PS: What is Bongo Bongo even supposed to be?
Conceptually? Evil spirit.
I never thought about it from that angle! That's probably it, honestlyI suspect that the Youkai called Tenome may have been an inspiration for it