Hitchhiker Nudibranch ID?

[Helio]

So I had found this on a plug that has been in my tank for a while. Wasn’t sure what it was so decided to take it out and put it in a bowl. What species is this?

 

[WheatToast]

From one of my other posts:
Looks like a harmless Elysia slug, which is not a nudibranch but still a type of sea slug. These will suck the “sap” out of some green algae and steal their chloroplasts to photosynthesize. I once had one that ate Codium, but ReefCleaners says they will also feed on Ulva, Penicillus, and hair algae. Ensure your pumps and inlets are protected to prevent the slug from being sucked up.
Elysia obtusa:

Elysia viridis:

 

[Helio]

From one of my other posts:
Looks like a harmless Elysia slug, which is not a nudibranch but still a type of sea slug. These will suck the “sap” out of some green algae and steal their chloroplasts to photosynthesize. I once had one that ate Codium, but ReefCleaners says they will also feed on Ulva, Penicillus, and hair algae. Ensure your pumps and inlets are protected to prevent the slug from being sucked up.
Elysia obtusa:

Elysia viridis:

Oh cool! I’m kinda glad as I didn’t want to get rid of it. I’ll put it back into the tank then.

 

[Seymo44]

Lucky….. lol
I’m always on the lookout for beneficial hitchhikers, but never come across anything unique.