Peter the Wild Boy, 1785

From Wikipedia 

PETER THE WILD BOY (born c. 1713; died 22 February 1785) was a boy from Hanover in northern Germany who was found in 1725 living wild in the woods near Hamelin (Electorate of Hanover), the town of Pied Piper legend. The boy, of unknown parentage, had been living an entirely feral existence for an unknown length of time, surviving by eating forest flora; he walked on all fours, exhibited uncivilized behaviour and could not be taught to speak a language. He is now believed to have suffered from the very rare genetic disorder Pitt–Hopkins syndrome.

Peter was found in the Hertswold Forest by a party of hunters led by George I while on a visit to his Hanover homeland and brought to Great Britain in 1726 by order of his daughter-in-law Caroline of Ansbach, the Princess of Wales.

Peter's grave is pictured at top, and the collar he wore so he could be returned if he ran away, below.

Peter could not talk and was mentally handicapped.

He lived to age 71 or 72 (longer than the King or Queen), with a royal pension to pay for his care.