What is this??

[Reefermadness98]

I have about 3 of these little guys that just sprouted up, they have a little tube in the middle of them. Sorry it's not the best picture, I hope it helps. Thanks everyone!

 

[reef lover]

Most likely a sponge of sorts.

 

[Rogued_Reefer]

Looks like a sponge Good sign harmless filter feeder.