The cartoon begins with Tom chasing Jerry in circles until he gets a letter that says his (identical) cousin George, who has a fear of mice, is coming to visit. Tom boards up Jerry's hole to prevent him from scaring George. But Jerry escapes and unexpectedly encounters George, who immediately tries to get as far away from him as possible.
Jerry, not knowing about Tom's cousin, believes that the terrified cat is Tom and tries several attempts to frighten him, including saying boo and pulling scary faces. But he gets confused when the real Tom shakes off Jerry's scaring and whacks him with his fist.
Having had enough of Jerry bothering George, the two cats play a trick on him by pretending to be a two-headed, four-armed and four-legged monster cat which terrifies Jerry and makes him flee the house and also overcoming George's fear of mice. A frightened Jerry runs to a house that has a gate with the words "Home For Mice With Nervous Breakdowns" and enters immediately.
- This is one of the few cartoons where Tom wins.
- There is a deleted scene where George and Jerry are walking outside.
- This is Cousin George's only appearance and he plays a main role.
- This episode also presents a new Tom and Jerry theme.
- On the notorious pan-and-scan version, when Cousin George changes the channels on the TV set, Jerry appears to be cropped out in certain shots because of the 4:3 pan-and-scan format, making it seem as if Cousin George is browsing through a blank TV channel in one shot.