In the very short career of the 19th-century Red Wolf, he accrued two Real American foes.
Devil Mask is the lesser of the two lesser lights. He's in the tradition of "Hound of Baskervilles" villains in that he wears phosphorescent materials to make himself look like a supernatural spirit of Indian provenance, sometimes called "Devil Mask." The hero initially thinks he's a white man posing as an Indian spirit, in part because the villain favors a six-gun, but Red Wolf finally figures out that he's a red man because of the distinctive way he mounts his horse.
Despite having a Roman name that technically means "she-bear," Ursa the Man-Bear at least supplies Red Wolf with a couple of lively fight-scenes. Ursa has a commonplace Tarzan-style upbringing-- that is, he's a fosterling raised by bears-- and as an adult he leads the bears like an ursine army, resulting in raids for which the white cavalry blames the Indian tribes. He appears to perish at the story's end and, to the best of my knowledge, never appeared again.