Nit-Witty Kitty
Tom’s chasing Jerry around Mammy the maid, when she accidentally clobbers Tom with her broom. This makes Tom think he’s a mouse, including crowding into Jerry’s hole and eating cheese. Neither Jerry nor Mammy are happy about Tom’s amnesia. Jerry tries to hit Tom again to change him back, but seems to have lost his aim (even a piano misses). A bowling ball does catapult Tom into the ceiling and change him back, but then on the rebound, he gets hit again and changes into a mouse again. Finally, a Rube Goldberg sequence triggered by Jerry’s carelessly tossed bit of cheese drops an ironing board on Tom’s head. Success! Except that Mammy, who’s reached the same conclusion as Jerry, happens along with a baseball bat and changes Tom back into a mouse.
Tom is concussed into believing he is a mouse, which puts Jerry in the awkward position of having a very large new flatmate. Identity-confusion plots gave the series a rare chance to change the relationship rather than simply repeat it, and the sight of Tom trying to fit into a mousehole is the payoff.
Amnesia caused by a blow to the head, played entirely for comedy; features Mammy Two Shoes.