Gama-chan

Gama-chan is Naruto Uzumaki's frog shaped wallet ("-chan" is a Japanese affectionate diminutive suffix, thus changing it's name from simply "ガマ" ("frog") to "ガマちゃん" ("Froggy")). Gama-chan's presence and brief appearances in the series are used for comic relief. Naruto cares for "Gama-chan" and refers to it as if it were a pet, saying that it's happy when it's fat and full of money. He gets disappointed and indignant whenever Jiraiya's jaunts out for "research" would end up with Naruto broke, and Gama-chan emaciated.

When Tsunade made a bet with Naruto on whether he could master the Rasengan in a week, she took a money-filled Gama-chan as his part of the wager.

Trivia

 * During the Three-Tails Arc, when Naruto asks Konohamaru to buy snacks for Gamatatsu and Gamakichi, Gama-chan's eyes lack the white border around them.
 * On the underside of Gama-chan, a white strip can be seen. The strip roughly says.