Any idea what this might be?

[SumpinFishy]

It is in the back of the tank in the shadows.
It is a live rock i added from my prior tank to help cycle this one. I don't recall any coral on this rock.
Looks like a pollup of some kind.
Thanks

 

[twentyleagues]

Looks like a sponge and some vermetid snails.

 

[Fish Styx]

Pineapple sponge.

 

[SallyWho]

OHHHHHHHHHHHHH, WHO LIVES IN A PINEAPPLE UNDER THE SEA

 

[Fish Styx]

OHHHHHHHHHHHHH, WHO LIVES IN A PINEAPPLE UNDER THE SEA