The Mouse Exterminator is a 1940 short animated film in the Phantasies series, produced and distributed by Columbia Pictures.
[1] It marks the final theatrical appearance of Krazy Kat, the title character from George Herriman's comic strip.
The mouse then shows up in front of Krazy, claiming to be powerless, and seemingly asks for mercy.
When the two shake hands, the mouse pulls Krazy into the hole until the cat's head is crammed in.
When Krazy returns to firing his rifle at the hole, the mouse repeats the same trick before pounding the cat with a mallet.