what is this bug (LEATHER CORAL ISSUE?)

[Lucafish101]

I noticed that my finger leather Coral wasn’t coming out and was staying all closed up and after 3 days I decided I to look closer and found this work looking bug. I’m not sure if it’s bad or not and can anyone explain why the coral is not coming out. The same thing also happened to my green star polyps that they won’t come out.

 

[ReQuackulous]

Bristleworm, I think they're in every tank hiding. Usually not an issue.

 

[SHNICI]

+1 for bristle worm
Just one think: try to avoid touching them with bare hands, you will get bristles and pain after. Otherwise everything else will be fine. Everyone have them