Gamamaru

The is the oldest and most respected toad of all the inhabitants of Myōbokuzan. Because of his age, the other toads affectionately call him. He is famed for his highly accurate prophecies.

Background
When Jiraiya was training at Myōbokuzan, the Toad Sage made a prophecy concerning him: Firstly, that he would go on to become both a talented ninja, and a pervert without equal. Jiraiya would walk across the world as a sage, "observing all creation, watching as nature takes its course," and in doing so he would also write a book. Jiraiya was also told that he would one day have a student with the power to save or destroy the world, and that it would be Jiraiya's actions that will determine which path this student takes.

Personality
Being several thousand years old, he is the oldest and most respected among the population of Myōbokuzan. At his great age, the Great Toad Sage seems to constantly smile and tends to have his eyes closed or squinting. He is portrayed and described as being senile, and sometimes out of touch with his present situation, so he does tend to forget things easily and quite quickly. However, when reminded, he is still able to remember things and can easily tell things very precisely. As a sage, he is also very wise, and is quick to stop Shima and Fukasaku from bickering and encourages harmony. It would seem that unlike most other toads, he actually has respect for Jiraiya, and has urged both Shima and Fukasaku to cooperate with him.

Invasion of Pain arc
Using the Telescope Technique, the Toad Sage watches the meeting between Nagato and Naruto. Jiraiya had originally believed that Nagato was the boy mentioned in the prophecy, but shortly before his death came to believe that Naruto was what the prophecy referred to. When he sees Naruto convince Nagato to sacrifice himself for the citizens of Konoha, the Toad Sage tells Gamabunta that both he and Jiraiya were wrong. The prophecy was about Naruto and Nagato. He wonders if The Tale of the Utterly Gutsy Shinobi really was the key to changing the world.

Fourth Shinobi World War arc
When Gerotora asks the Toad Sage if he should give Naruto the "key" to the Nine-Tailed Demon Fox's seal, the Toad Sage has Naruto brought before him so that he can make a prediction. He foresees that Naruto will meet a "creature with octopus tentacles" and will battle a "young man with powerful eyes". He also sees that Naruto will be given the key, so instructs Gerotora to go ahead.

Trivia

 * The Great Toad Sage wears a necklace with the kanji character on it. It is frequently used in reference to toads in Naruto.

Quotes

 * (To Fukasaku and Shima) "No fighting, children. A husband and wife should be nice to each other."
 * (To Gamabunta) "It's over... As it was foretold...but I never thought Jiraiya's two pupils together would be the children of prophecy, the ones to lead a revolution in the ninja world. Maybe...this was all meant to be from the time Jiraiya decided not to give up... That book really was the key to changing the world."