I’d probably go with a huxian (狐仙). I mean look at the benefits:

1. Shape-shifting out the door. That’s always fun.
2. Since they’re on a path to becoming an immortal (仙) there’s less of that morally grey area that the huli jing (狐狸精) bring with them. I mean sure, seducing scholars to trick them could be great fun (geeks and nerds are my type), but it’s not really conducive to immortality, is it?
3. As a huxian I’m revered by the people who encounter me (as opposed to the huli jing who is often villainized and chased out).
4. Through “inner alchemy” (内丹) I cultivate in myself ever increasing magic powers like weather manipulation, herbal mastery, and astral projection.
5. In the end I become an immortal worshipped by scholars and others and can even start mentoring scholars who are cultivating themselves.

And all that without the tediousness of tending to Inari’s whims (kitsune) or being in a predatory cycle with no form of cultivation or improvement (gumiho). I’m just a well-regarded philosopher-fox.

One of the extra dimensional beings eg, Q or Metron.

I wanna be a bog witch living off mushrooms and toads.

Legit, werewolf, out of the standard stuff, but only if my mind is my own when in the other form/s. If I can’t remember it, or don’t have control of it, fuck that. But if I could turn into an animal and fully live the experience? Fuck yeah. Can’t say a wolf would be my #1 choice, but it’s the default kind of therianthrope in western media. I’d wanna be a tiger if I had full choice

However, if it isn’t within that criteria, I think I’d have to go with something like you picked, because there’s a greater chance of it not being some kind of bullshit. Pretty much every traditional version of a “witch” is just a person with abilities of some kind to work magic. That’s a doable situation.

Stuff like vampires, it’s back to the “what kind”, even though that could be a lot of fun.

Can I be a pokémon?

I’d be a Time Lord for sure, does that count? If not then I say a witch too. Specifically one connected to the sea.