(WARNING: Major spoilers abound!)
Popeye and Olive Oyl attend a performance of Bluto, “The Great Hypnotist.” But even though Bluto levitates a drum and makes a cane walk off the stage, Popeye says, “I don’t believe in such t’ings.” (Bet’cha Popeye couldn’t do that stuff even after eating a can of spinach.)
Bluto hypnotizes Olive Oyl into coming onto the stage. He then convinces her she’s a chicken, and she does a frighteningly accurate impression of one, to the point of laying an actual egg.
Popeye blows his pipe and then his fuse in frustration, uttering for the first time in a cartoon, “That’s all I can stands, ’cause I can’t stands no more!” Popeye jumps to the stage to fight Bluto. Bluto tries to hypnotize Popeye into being a monkey, but Popeye puts a full-length mirror in front of himself, sending the “whammy” back on Bluto, who turns into a climbing, shrieking monkey.
When the spell wears off, Bluto hypnotizes Popeye into being a donkey (looking an awful lot like the spellbound Pinocchio in Walt Disney’s later feature-film cartoon). Popeye’s spell wears off as well, and when the inevitable fight-and-spinach ballet goes on, Popeye tugs at Bluto’s turban and flips him out to the balcony like a yo-yo. Olive-as-chicken returns, and Popeye knocks her back into reality for the final shot.