What is this thing-good or bad?

[Ron99]

I think I have one of those too! It's kind of a pale pinky purple with white tips. It has never moved and is in a fairly dark shady spot. Is that normal for these or is the fact it never moves mean it may be something else?

[noirsphynx]

I'm not sure if they move or not(mine never have) but they are nocternal.

[traco]

So, yay, it can stay. It is down lower and not in direct light. So no worries about it stinging corals.