The Cat Bell (鈴 Suzu) is an item used as proof of being sent to see Kami at The Lookout.
Goku receives the Cat Bell from Korin on Korin Tower and shows it to Mr. Popo, to prove that he is qualified to challenge Mr. Popo for a chance to see Kami.
A similar bell is on Mr. Popo's cat. When Goku needs to learn about seeing without seeing, Mr. Popo blindfolds him and asks Goku to catch the cat, who has the bell tied to its tail.
During the battle against Garlic Jr. and the Spice Boys, while waiting at Korin Tower, Maron wins a Cat Bell from Korin in one of the many poker games she won against Korin and Yajirobe.
Video Game Appearances
The bell appears in Dragon Ball 3: Gokuden, serving the same purpose as in the manga.