Yknow, I've seen a HP fic where the protagonist obsesses over animals, but I have never seen one where the protagonist gets loved by animals. (If you know one please tell me, I want to read it)
Honestly my thought of this idea came from someone's post saying that they want to mate with spider girls (like in undertale). And I thought of harry potter for some reason. I mean, there are a lot of magical beings in HP (I am running out of ideas)
Honestly if this is too boring you can go full degenerate mode and make the protagonist able to turn them human-like. I kind of do not read fics with a harem seeking protagonist tho. You might like it, but I like when it happens naturally.
(off topic)
Well, Payday 3's launch is a disaster. Also I am not used to the new webnovel UI. No more seeing numbers go up on views i guess.