Gamahiro

is a toad comparable in size to Gamabunta. When summoned during Part I, he wasn't named. It was not until Part II that his name was revealed. He carries two large swords on his back.

Invasion of Konoha Arc
His first appearance was in the Konoha Invasion, when Jiraiya used him to fight Orochimaru's large snakes by using Summoning: Food Cart Destroyer Technique. Jiraiya summoned him again later in the anime to help Sasame, Sakura Haruno, and Naruto Uzumaki escape from Orochimaru's hideout.

Invasion of Pain Arc
Gamahiro made his Part II debut when he, along with Gamaken and Gamabunta, were summoned to assist in Naruto's fight with Pain. They fought the various animals summoned by the Animal Path until they were sent flying beyond Konoha's borders by the Deva Path's Shinra Tensei technique. After the battle, he is last seen lying at the bottom of a lake.

Trivia

 * When Gamahiro first appears in the anime, he is colored green and brown. This is updated to a bluish color for the Invasion of Pain arc, keeping with the manga's coloration.
 * In Naruto Shippūden: Ultimate Ninja 4, a miniature version of Gamahiro appears as a catchable toad that is called "Professor" due to his interest in geography and such. He wears a teacher's hat.