Can you identify this?

[misfire250]

I recently picked up some live rock from someone getting out of the hobby and placed it in quarantine. I just noticed something started growing on part if it. It definitely has some fluorescence. There are very short "tentacles" and it looks to have a six spoke pattern. Does not look like anything I know of but I'm pretty new to this. Any help? Thanks!

 

[misfire250]

Here are some better pics. Thanks!