The following images, which I'm sure will haunt you until you expire screaming on your death bed, are of a rare type of tumor called cystic teratoma which are the ugliest things to ever come out of the human body (and that includes Clint Howard and shit).
Fittingly, the name means "monster cancer". They can occur anywhere in the body but are most infamous for growing on the eyeball... the tumor has stem cells and, so... it grows hair though, elsewhere in the body, they could grow bones, teeth, nerve cells, or blood vessels.
Enjoy. If you just ate... I'm sorry.