Nudibranch? Sea hair? What is this?

[90sShooter]

I just found this critter walking around and want to make sure he is not gonna eat my corals...

Can somebody please ID this for me? Good or Bad?

 

[greenbean36191]

It's Aplysia, which is a sea hare. I would guess it's probably A. parvula, which luckily stays very small.

 

[90sShooter]

Thanks for the ID greenbean! I looked it up and it looks like a perfect match! But I can't really find much info on them... Are they good or bad?