What is this?

[philosophile]

I just bought some more live rock to put in my tank, and I found this in one of the crumbly bits.... So I put it up higher, on another piece of live rock. Is this a mushroom coral? Is it some harbinger of doom for my green chromis and peppermint shrimp that I just added?

Care information would be helpful too, if it isn't something I should pull out.
121351

[mdhyde]

It's a mushroom. A good thing!!! not the kind you would eat, but nice to look at. They also split and multiply if tank conditions are decent.

[philosophile]

Yay! Free coral! I was going to add some coral later down the line, after my tank had some more time to mature. I guess this little one will be my sputnik monkey.