Truuue. I'll probably stick to species we've seen in the Ponyhammer universe though...
Wait! From outside the galaxy! Nvm I'll use anything that seems cool. xD
Thanks for the thought!
Just remember to stay away from the beasts shown in the show, because Chaos needs love too. I am certain that Rhinos would make great deamons for Khorn, and that Chimeras are too messed up to not
be Tenzichian servants. A literal reskined Manticore would make a rather off-putting Slanishi beasti ( look out for that tail!), and.... lumbering putrifing bears for nurgal? Even the most evil bear loves her cubs.
Meh, worth a shot. At least we would be seeing massive rotting piles of bear flesh lumbering towords doomed ponys while pony sized cublings leak out of the putrid rips and holes on it, slowly filling the landscape with pus and other nasty things, while a half-insane Chimera argue with themselves(?) about the details on there plan on ending creation a planet away.
Griffons could be a Xenos species used by the empire, al la Ogron, but more compitent, because they just dont scream " just as planed!" OR "blood for the blood god!" to me, nor do they seem stupid.