Zanthar

Xanthar (also known as "the being whose name must never be said") is a character in Gravity Falls, apppearing in the episode "Weirdmageddon Part 1."

History
Xanthar was one of the monsters that entered Gravity Falls in "Weirdmageddon Part 1", and later followed Bill to the Fearamid.

Appearence
Canthar walks on all four of his legs, has dark-purple skin and no face. In it's place is just a light-purple form. Small trees are growing out of his back and shoulders, and he wears a party hat.