Feather duster worm?

[medusala]

Hi, wondering what this is. It attaches its foot to the bottom surfaces, and is quite active.

I'm thinking it's a feather duster worm? Harmless? Thanks for your help!

 

[Lionfish Lair]

Beautiful! You don't see that too often. Yes, it's a little feather duster.

 

[medusala]

Oh really? They are relatively rare hitchhikers?

 

[Lionfish Lair]

You usually don't see them without their tube/hole.