Legion creature

 is Ghoul living in the Mojave Wasteland in 2281.

Background
Legion Creatures are Ghouls who are in Caesar's Legion. The name probably came from other Legionarries beacuse they don't think Ghouls should be in the army or because they think Humans are surperior than Ghouls.

Appearances
should have appeared in Fallout: New Vegas, but it was cut for some unknown reason.