Official Lol Cannon
Having a quick look over the tyranid codex I noticed that nearly all the HQ units are psykers. Would it be possible for chaos to corrupt the tyranids or a daemon to come possess one of them?
It would be more like getting cancer. Nurgle infests one hive ship, so the rest of the Nids would isolate it, if possible destroying it.I personally don't like it for thematic reasons.. It would be like some of a person's brain cells becomming possessed while the rest of the brain remained normal..
But the spank has never formally gone down as far as I'm aware so yeah, I guess there's room for chaos nids..