new starfish! ... i think?

I was checkin out my tank yesterday and saw a tiny little white thing movin along on a piece of dead coral in my tank. I did a double take and got a closer look, it looks to me like it might be some kind of star fish. I did not purchase him, and i havnt bought a piece of LR in at leat 6 months. It's really small, only about the size of my pink nail. I have about 60 lbs of LR in there right now. Any one think they know what it is, how big it might get and how it might grow? is it reef safe?
i prolly wont see it again for at least a few weeks. He's prolly stay lost in my LR pile for a little while, but if when i see him again I'll try to get some better shots...

there should be some pics attached...

 

Asterina star, stays about the same size. They come in on LR and frags.

 

Yeah, its a starfish. I don't remember the name but I will look for it. Not bad, they get to be a little bigger than a dime.

 

cool thanks guys

 

congrats!