Is this a bristle worm?

[Markclaster]

What do I need to do about it? Anything?

 

[kullas]

Looks like it to me. Some people hates them some dont mind them.

 

[Markclaster]

Looks like it to me. Some people hates them some dont mind them.

Will it hurt anything?

 

[kullas]

You if you brush against then. Not bad. They eat detritus so it's a trade off. I get rid of them if I see them but dont go out of my way to get rid of them

 

[AG36]

Looks like you have a reason to get a wrasse in your tank LOL !
Arrow Crabs are often documented to rid your aquarium of bristleworms as well as Coral Banded Shrimp.