What the…?

[zbrusko]

Are these sweeper tentacles?

 

[jsmkmavity]

Maybe hydroids?

 

[dilligaf2929]

Hydroids get some bumble bees snails

 

[Tahoe61]

Ctenophora is what it looks like to me.
https://www.reef2reef.com/threads/ctenophore-comb-jelly.334470/

 

[DSC reef]

Looks like mesenterial filaments

 

[Mr. Mojo Rising]

To me it looks like some kind of webbing from some kind of tube worm

 

[zbrusko]

Ctenophora is what it looks like to me.
https://www.reef2reef.com/threads/ctenophore-comb-jelly.334470/

Looks an awful lot like this. It was attached to the fleshy part of the coral, so I thought it was part of the coral. But the photos in this link are very very similar.

 

[Tahoe61]

Looks an awful lot like this. It was attached to the fleshy part of the coral, so I thought it was part of the coral. But the photos in this link are very very similar.

Yes, while you don't see that much in the hobby, I have received them a good number of times on Sarcophyton aka Toad Stools, and other soft corals.

Personally I think they're pretty cool.

 

[zbrusko]

If they’re not a big problem, I’ll put them at the bottom of my current battle list of dinos, vermatid snails, and aiptasia!