Any idea what these are growing on my Zoa rock?

[dustinkimpel]

These took over the rock my zoas are growing on but I'm not sure what they are. They act like mini corals (they retract sand stuff when you mess with them) Any help is greatly appreciated!

 

[taricha]

Zoom in and you can see each polyp has 12 tentacles.
Looks like some sort of encrusting sps.
Beyond that, I'll leave it to someone else.

 

[m3t411ic4]

Post in the SPS forum and I'm sure someone will tell you exactly what that is.

 

[Budman422]

Maybe a porities