I read somewhere (on the internet, so it must be true) that a lot of the supposedly "feral" children either found in caves or raised by wolves / chimps etc. were actually mentally handicapped children, unwanted by their parents who considered them a burden, and palmed off on missionaries or local colonial authorities.
Found in 1867 inside a jungle cave, this feral boy named Dina Sanichar, preferred eating raw meat, had trouble standing on two feet, growled like a wolf, and gnawed on bones to sharpen his teeth. He never learned to speak. He became the inspiration for The Jungle Book's character of Mowgli.