The Eyes Have It(1945)
Donald receives a mail order hypnosis kit complete with hypnotic goggles and decides to test it on Pluto. Using the goggles, he convinces Pluto he is a mouse, a turtle, and a chicken. Each "transformation" Pluto undergoes Donald finds extremely funny so he keeps at it until he notices chicken Pluto getting into a fight with a rooster. Donald helps Pluto win the fight by making him think he's a lion but, unfortunately, the goggles break and Donald is chased about by Pluto until he regains his senses after a fall.