An epiphany of thought. When someone suddenly has a brilliant idea.
omg, i just birthed a brain baby.
by Volcanis July 19, 2011
Anything with an overly large head, or anything that looks top-heavy in any way.
Man, did you see that psychobilly, brain baby thing over there? it's head was all greasy and stymie like rubber johnny's.
by Angus_for_president November 26, 2007