Cubone is my favorite of the original 150. I really like the simplicity of it's design, and it's seriously morbid that it supposedly wears the skull of it's mother on it's head. That's a bit dark for a mass-marketed children's video-game, isn't it?
Maybe you can psychoanalyze a person by their favorite Pokemon. For instance, what Cubone's face looks like is unknown - it hides it with that skull.