Season 1, Episode 2 of ALF: The Animated Series.
When Gordon makes his pets and his sister Augie bald, he goes back to Madame Pokipsi in disguise for a cure. She will only agree to cure him if he goes on a long journey get her the legendary golden egg from the horned beast on the highest mountain peak. Gordon instead quickly absconds with her crystal ball.
Madame Pokipsi then transfers her lizard Eugene into a giant monster and sends him to pursue Gordon, who meanwhile tries to reverse the curse with the crystal ball. He is able to alter his curse so that he is now able to transform things, but he is unable to totally control it. When he finds out that Harry had stolen his hair, he turns Harry into the legendary golden egg and gives Harry to Madame Pokipsi in exchange for removing the curse.