I’m jumping on the Sk’ar train. Here are my headcanons:
He constantly smells like a field of wildflowers. This is very odd but also very intimidating because if you’re alone in the middle of the night and it suddenly smells like a bunch of flowers, you know that terrifying giant purple fucker is near.
He doesn’t trust anyone farther than he can throw them. He found this Imperial saying very fun because he takes it very literally. Whenever he meets a new potential ally, the first thing he does is go to shake their hand, then grab them and throw them as far as he can. So far this method has 100% accuracy.
He models himself after the god Grievous, who he has no idea is his old buddy Qymaen. Like, he knows Qymaen started calling himself Grievous, but didn’t put two and two together so incidentally he worships the same guy that he’s probably seen throw up.
He survived one explosion and thus thought himself unexplodable. Chewbacca proved him wrong.