Gama

is the first toad named in the series. Gamachu is a mid-level toad that first appears when Jiraiya is introduced. Gamachu is always seen wearing samurai armor in battle. When he first appeared in the manga, Gamachu seems to strike the same type of pose as Jiraiya, as he would also seem to have become the personal summon of Jiraiya. This toad seems to be the keeper of the Toad Summoning contract scroll and unlike every other toad ever seen, Gamachu has not yet been seen talking, only quaking once or twice and mainly in the anime.

Chunin Exams arc
He is first summoned to tongue-whip Ebisu for annoying Jiraiya at the hot springs. Later on, he's summoned once again to give the contract scroll for the Gama family to Naruto Uzumaki. There he stayed for a little while, while watching Naruto fail in summoning a real toad.

Return of Itachi arc
Jiraiya later summoned him to deflect Kisame Hoshigaki's attack on Naruto Uzumaki.

Search For Orochimaru arc
Gamachu was summoned again to save Naruto from one of Kagero Fuma's attacks.