Mushroom like thing

[Katfsh]

Ok today I noticed a Mushroom type "thing" in my tank growing on a rock that a leather I bout about six months ago is attached to. I tried to get a picture of it but is just in a bad spot. It is less than a 1/4 of an inch in diameter and is flat like a mushroom. It is bright green but what is throwing me off is that it has little arms all the way around it like a zoa but the are very very small, and there is also some that stick straight up off of the main disc. Any Ideas on this?? Thanks

 

[Anonymous]

Like this? This is a baby fungia an LPS

 

[Katfsh]

that looks like it.. I wonder where it came from

 

[Anonymous]

They seem to be pretty common hitchhikers be it on new LR or frags. Anyway it's a freebie