That's modeled after the conventional image of the grey extraterrestrials - the larger skull, eyes (though that'd require explanation), etc. (Plus my comment in the title.)
Doesn't have to. From the perspective of those who unwisely reject the concept of conspiracy as a reality, we all just fit into one lumpy category. They grasp the simple concept of ETs and UFOs, however, so an extraterrestrial head for humor :-)
Actually I just saw a video on Sumerian Texts revealing that God could have very well been aliens. It's really mostly accurate. You should search that up some time.