Help ID please. White critters on glass with two antenna?

[Aeyeonee]

Help ID please. White long critters on glass it seems they are still with tiny two antennas. Is this a worm or parasite?

 

[Idoc]

#reefsquad -- Anyone have any specific ideas on these things?

 

[KingTideCorals]

Looks like some odd kind of worm/hydroid!

 

[Aeyeonee]

Looks like some odd kind of worm/hydroid!

I wonder if these are bad pests..?

 

[KJ]

Hard to tell from the pic! Resemble spionid worm with out the tube.