Gerotora

is a "scroll toad", a rare species that closely guards whatever secret is written on its scroll-abdomen until his contractor dies. He resides in the body of his contractor, and is known for his excellent endurance.

Gerotora guards the scroll which acts as the "key" to the Eight Trigrams Seal on Naruto Uzumaki's stomach. The key is left to Jiraiya after the death of Minato Namikaze, and Jiraiya in turn leaves it to Naruto when he dies. Gerotora voices his concern about this, pointing out that the key is being left atop the very "safe" it opens. He also does not think Naruto is ready to tamper with the seal. Jiraiya said that Minato gave him the key's jutsu design as a sign that Minato intended Naruto to complete an unknown jutsu.

Hunt for Uchiha arc
He first appears when Jiraiya summons him, so they could talk about Naruto's key. Jiraiya wants the scroll to go to Naruto since he thinks that he was going to die. Gerotora angrily refuses, believing that Naruto isn't ready, but had no choice.

Gerotora was one of the toads (Fukasaku, Gamabunta, and Gamakichi) to visit Konoha to bring news of Jiraiya's death.