Need help identifying friend or foe invert!

[Le Dirk]

I’ve had these Zoas for a while now but never ever seen whatever’s on them until now, I’m a college student so my parents take care of my aquarium while I’m away. What is this? Is it a friend or a pest?

 

[reeftivo]

can't tell by the pic

are you referring to the purplish stuff? one of those protruding looks like it might be a vermetid snail tube.

have the zoas ever opened fully? if vermetid snails, that would explain if they aren't opening. they lay out a mucous web when feeding that can irritate near bye corals.

get a better pic up if you can

 

[MischiefReef]

Vermetid snails from what I can see. Also bubble algae. Both nuisances, crush/glue vermetids and remove bubble algae with some hydrogen peroxide dosing/running some carbon and also bringing down PO4.