From Gaunt's Ghosts: In additon to Loxatl, there's whatever Desolane is from Blood Pact; 'a slender, sexless creature' with short horns, and a gauze cloak that moves like smoke - not sure if racial item or stolen/commissioned. There's also at least one race including or comprised of what we would call Minotaurs. There's a big-ass slug, race name not provided, and a creature called a Jehgenesh, but they are warp-based and thus are arguably Daemons. Ogryns can also serve Chaos, although usually unwittingly (what do they want that a Chaos God can give them?) or after extensive modifications into once/twice/thrice-wroughts.