they're very shy and polite, preferring to take ignorable shapes in corners when around groups they dont know, or dont know well. if you still bother them in hiding mode, or betray them by freaking them out in personable form, they'll just eat you

they can also pull an ancubus and read what a person wants to s33 and take that shape. however this can also play out in sfw ways- if you'd stumble upon them and they dont have time to Hide Properly, and you like cats, theyll be a cat. etc