White Snake Sage

The is the leader of the snakes and resides in the Ryūchi Cave.

Background
At some point, Kabuto Yakushi came to it and under its tutelage, the shinobi learned senjutsu and mastered the snakes' equivalent of Sage Mode.

Personality
In the anime, Orochimaru referred to the White Snake Sage as a being with an eccentric personality and very dangerous to deal with. She has a strict policy only letting her subjects eat any intruders if they first fail any of the given tests to meet with her. Overall, the sage is shown rather laid-back and uninterested in matters that don't directly involve Ryūchi Cave.

Appearance
The Sage is an extremely large, albino Japanese rat snake, many times the size of a human with its massive body wrapped in thick coils. Along these coils are yellow circular bands. It wears a turban with two pointed edges and a red orb on top along with an orange headdress. It also wears a chain with a green orb around its neck, similar to the one worn by the Great Toad Sage. Because it has lived in the cave for so long, its body has grown together with the ground. The Sage smokes as well, using a long cigarette holder when doing so.

In the anime, the Sage is able to take on a humanoid form. She appears as a plump elderly woman of pale complexion and short stature. She also retains her snake eyes. In this form, she wears a white kimono an orange veil and black cap on her head.

Abilities
The snake uses its fangs to bite and inject a person with natural energy. According to the legend, if the body can withstand the snake-ification, the White Snake Sage will accept it without reservation. Otherwise, it will devour it whole. As a Sage, it is very knowledgeable in senjutsu as it taught Kabuto how to use senjutsu and Sage Mode, which he mastered.

Mitsuki Arc
In the anime, the White Snake Sage granted an audience with Boruto Uzumaki after he passed through the Ryūchi Cave's trials. When asked to analyse the snake he brought in hopes of learning more about Mitsuki's departure, the sage refused, saying the trials Boruto passed were about earning the right to learn senjutsu. Boruto insisted, and the sage agreed to help him if he brought the sage Garaga's reverse scale, though the sage fully expected Boruto not to survive the attempt.