Okay, thinking about it, that twitter artist already covered a lot, so now I need less than I expected. and the Shifting Mound is a given since that's her 'true' form.

So...trying out Stranger for now, as a test run for Mound, since that one has a lot of extra heads and arms, so this is to see how AI handles that. Go for blue eyes and blonde hair. Dress can be whatever, though I'm partial to purple.
Just the upper left is fine if the anon doing deliveries doesnt want to do everything.
https://vignette.wikia.nocookie.net/slay-the-princess/images/0/0a/Stable_Stranger.png