LFS thought same thing. They haven't hosted my anemone yet, so I don't know what could be doing it. Hammer?
I've had all my fish for over a year. I did tank transfer on them all. However, I've added frags here and there. No signs of this on the blue hippo, tomini, scribbled rabbit, or the 6-line wrasse.That looks like a Paravortex or Turbanella worm infection, otherwise known as black ich.
What was your QT regimine with this animal?