Worm(?) ID

[proace360]

Noticed this worm-like thing on the base of my frogspawn the other day. I've seen the tentacles quickly retract and come back out so I'm assuming it's some kind of worm?

 

[Reefkeepers Archive]

Noticed this worm-like thing on the base of my frogspawn the other day. I've seen the tentacles quickly retract and come back out so I'm assuming it's some kind of worm?

That's a featherduster. Very common and completely harmless/beneficial filter-feeders, alot of tanks will have dozens of these, nothing to worry about