Yuma's is an old Conqueror woman, and also Shane's tutor. Her (forced) spirit animal was an earthworm.
In the Books
Yumaris first appears at a Conqueror assembly, where she holds Drina in place as she is murdered by a controlled Iskos. As Shane is silently counting down to Abeke from across the room, Yumaris realizes what he is doing and shouts a warning.
As Shane is wandering around his father's castle, Yumaris appears and gives him a sword, telling him that "words and learning do nothing to impress a jackal."
Yumaris is hunted down by Shane, who plays right into her scheme of having him save the world from the Wyrm.
Now blind and slightly mad, who thinks she is an earthworm, she can still keep tabs on the Four Fallen and their human partners, as well as navigate in the underground.
In Heart of the Land, she loses her mind even more. Still being able to act as the Redcloak seeress, she tells Stead and Worthy of the The Four Gifts of Erdas, in which she describes as the 'rock, claw, circle, and the other thingie.'