Id please. It came with the coral

[Illapino83]

It came with the coral. Im acclimating the coral i just bought and saw this thing on the rock. Its shrunk right now i guess. Im not sure of what it is.. anyone know?

 

[GHsaltie]

That's a montipora eating nudibranch, and I would venture to guess the source of the damage on that coral. Remove him ASAP and check thoroughly for egg cases. Also run the coral through a dip if you have any.