ID Please

[pet22]

filter feeder, sort of brown.
When I poke them they retract, but the stem/tube stays there and is sorta rubbery.

Those bambams are 1/4 inch for reference

 

[Jeffcb]

Aiptasia. A peppermint Shrimp will get rid of it.

 

[WheatToast]

Aiptasia. A peppermint Shrimp will get rid of it.

Aiptasia does not retract into a tube when disturbed. My guess is that these are colonial hydroids.
https://www.reef2reef.com/threads/colonial-hydroids.441987/