Guerrino and the Savage Man
Guerrino and the Savage Man is an Italian literary fairy tale written by Giovanni Francesco Straparola in The Facetious Nights of Straparola. It is Aarne-Thompson type 502 titled "The Wild Man as a Helper" and is the oldest known written variant of it.
Source: Wikipedia — Guerrino and the Savage Man (CC BY-SA 4.0)