Is this a parasite? Should i be concerned?

[reef.geek]

Hi everyone!

So i purchased my first coral today and i noticed that it has a hitchhiker on the rock it came with

Is this a parasite or what am i looking at here?

Thank you in advance

 

[Tahoe61]

I can't make out a definitive ID, but I do see bubble algae and a vermetid. Remove the frag, put it in a separate container with tank water and scrub entire plug with a soft tooth brush and then return frag to aquarium.