A little help with identifying

[Katabug0303]

Hi. I’m new here but need a little help. My mom set up a nano tank last week and put live rock in it. So…we got a few hitchhikers lol. Everything that’s been appearing we have been able to identify so far. But this isn’t something we can find info on. It looks like a type of starfish to me. I can see it’s little “feet” wiggling around under it just barely. Can I have a little help finding out what these are? There are two in the tank I can see now and look identical to each other.

 

[Spare time]

Asterina. I'd just pluck them out. Some people don't like them as they can grow to large numbers. They are not harmful.