"OPO"

Okay, so it's an octopus, obviously. but its bifurcated cranium seems to suggest that it's intended as a monster of some sort, and I believe that the squiggly lines in the middle are evidence that it's intended to be transparent, with the tangle of lines representing its internal organs. And, apparently, its name is "Opo" (possibly inspired by "Ocho", the pet octopus from the Hanna-Barbera Addams Family cartoon), unless those are supposed to be lumps or spots on its skin that were too sloppily drawn. I'm pretty sure that's his name, though.