Quote Originally Posted by Grif View Post
Seconding Paranids. Ponynids just sounds weird no matter how you slice it.

(Though are they still xenomorphs? Though impossibly cute? Don't think we got a picture of them. Though if they're xenomorphs AND cute, I'm totally abusing Pokemon for reference.)
Rippers: Parasprites.
Hive Tyrants: Vessel of the Hive. Appears as a normal pony, but can mutate pretty much on whim. Has parts of their original personality, but, as their name suggests, are mostly just The Hive-which is made of EVERY personality.
Carnifexes, Trygons and Other Big Things: Pretty much the same as warhammer canon, or some other large scary monsters.
Everything in between: Ponies, but often with added spikes.

I'm drawing on tyranids with a little bit of Borg here, and adding some random other bits cause I feel like it.