This weird little sculpey looking alien came from the dollar tree in the late 90s and it's such a distinct, imaginative and highly detailed design but it isn't from anything. It's also a stamp but obviously very dried up. There was just one other thing in the set, a robot spaceman counterpart.
IMMEDIATE UPDATE I moistened the stamp and it's like brand new. Also, the stamp is just the same nameless alien's face.
You could never even possibly know what this is a stamp of without seeing the entire thing first.