Here is a better photo.
I think they are bad, I fond a few mixed in with a piece of Clove Poyls that doesn't look good at all.
I think they are eating them.
If they are bad will they eat other corals as well?
How do I get rid of them all?
Its the thing right in the middle of the photo. Above the red algae spot (there are accually 4 all around the big one.)