A neon green hammer coral of all things! Has anyone ever experienced this? I'll try to put a picture up. Very mobile brown patches that irritate the tentacles making them over inflated to the point that you can't tell that it's a hammer.
Can you post a picture of them? Are they aeolids?
I am pretty sure these are not aeolids. These are smooth flatworm shaped creatures with a tiny raised bump in the center. They seem sticky and they move quite easily all over the coral. The best I can describe is "slither" or slide. There is a pink hammer close to it that does not have this infestation. That said, the 2 hammers do not touch at all.
Well, I would dip the corals that are affected to reduce their population.