A sane human being. Everything about children is worth hating. They remind us of our former innocence and our present... sullied state. If you look a child in the eyes without hate, it is only because your soul (the place where your shame lives) has died.
It is only rational to hate children
"Dude, why do you always looked so pissed off?"
"I'm a childhater."
"Whoa... what a dick."
"I'm also a youhater (see: youhater)."