Need an ID on this thing!

That would be a primo hitchiker if so.

I got cup corals on another rock actually, ugly version though (white/clear almost), but hey it was a coral for one a few dollars. Guess the guy I bought from didn't realize what he was selling, as he thought the cup corals were anemones and must have no seen this :). I hope it is good. It doesn't look like a limpet thou.
 
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