Lord Surtur is humanoid. He is an omnivore.
Yet first was the world in the southern region, which was
named Muspell; it is light and hot; that region is glowing
and burning, and impassable to such as are outlanders and
have not their holdings there. He who sits there at the
land's-end, to defend the land, is called Surtr; he brandishes
a flaming sword, and at the end of the world he shall go forth
and harry, and overcome all the gods, and burn all the
world with fire.
The Prose Edda, by Snorri Sturluson