Gamamaru

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

Background
When Jiraiya was training at Mount Myōboku, 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
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 watched 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 saw Naruto convince Nagato to sacrifice himself for the citizens of Konoha, the Toad Sage told 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.

Confining the Jinchūriki Arc
When Gerotora asked the Toad Sage if he should give Naruto the key to the Nine-Tailed Demon Fox's seal, the Toad Sage had Naruto brought before him so that he could make a prediction. He had foreseen that Naruto would meet a "creature with octopus tentacles" and would battle a "young man with powerful eyes". He also saw that Naruto would be given the key, so he instructed 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 "Child of the 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."