Great Slug Sage

The is one of the Three Great Sage Animals alongside the  and. He is a resident and the apparent leader of the famed Shikkotsu Forest.

Background
He was a member of the first generation alongside the Great Toad Sage (leader of Mount Myōboku) and the White Snake Sage (leader of the Ryūchi Cave). Both three of them fought together and with their respective wisdom and age, they founded the three legendary places where the toads, snakes and slugs inhabit. All three of them apparently retired and named Gamabunta, Katsuyu and Manda as the new generation of Three-Way Deadlock. Having retired, they serve as the elder of their respective residence.

At some point, he also taught Hashirama Senju how to use senjutsu.

Appearance
The Sage is a huge slug, many times larger than Katsuyu. His shirt bears the kanji for "Sage" on its back.

Abilities
As a Sage, he is knowledgeable in senjutsu as he taught Hashirama Senju how to use Slug Sage Mode.