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'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. He voices his concern about this, pointing out that the key is being left atop the "safe". He also does not think Naruto is ready to tamper with the seal.