Not a worm?

[jrock flimflam]

Tank has some cyno which is what I believe the red is on it. It is attached to, or coming from behind, the shell the PX came on. It is not a worm as it never moves or retracts. It is slowing getting longer over the weeks. I keep expecting to see a flower bud on the top as it looks like a plant stem to me.
Any suggestions?

 

[vetteguy53081]

This appears as a tube worm or spinoid worm

 

[Sean Clark]

I think I just... yep... that's... eww...

 

[JGT]

Looks like algae stem to me covered in cyano.