IDENTIFY! What is this thing?

[saltman1968]

I apologize for the fuzzy photo below.
This bulbous thing about the size of a large marble is located just under my mushrooms, it is growing! It is white and looks like it has "tentacles" with a fuzzy texture to it. It looks like tapioca pudding in a ball...

 

[star master]

I have something exactly like that and it has been there for 5 months. I find that it is harmless but still do not know what it is.

 

[spanko]

Probably some type of sponge.

 

[alyssia]

Looks like a sponge

 

[reefmate75]

i have alot of them, they are sponges...freaky looking huh hahaha

 

[saltman1968]

Reefmate: do you have any photos of your "sponges"
I have to assume its harmless...