did I get a starfish with my live rock?

[artbymollie]

this showed up about 3 weeks after I added my live rock so far I havent added anything to my tank other than my sand, rock and water. I know I have about 3 snails and a few tiny little critters climbing around on the rock like pin tip tiny that came with the live rock. Im waiting for my tank to cycle, I have tested the water once a week since I started it and It has just now started to show a little nitrite but no ammonia spike or any thing. so Ill keep testing and waiting.
anyway anyone have any idea what this is

 

[meowzer]

It is an asterina star.....they do not get much bigger. They multiply really quick too....IMO they are good tank cleaners
BUT they can also take over...LOL...when I start to see A LOT.....I remove some and toss them

 

[snakeblitz33]

Yup, that's an astrina starfish. Good thing. Just keep an eye out for em' when you start adding zoas. Some of them like to munch on them. Nice pic.