Is this Aiptasia, Hydroids or some type of tube worm?

[jport092]

I've recently discovered these growing out of the side of some new live rock I've obtained. Any feedback on what these are would be greatly appreciated. Thank you all.

 

[Mark9]

Looks like yellow polyps, not aiptasia.

 

[jport092]

Awesome. Thank you! I was starting to get worried

 

[tmz]

Parazoanthus, a colonial anemone often called yellow polyps.

 

[skp]

Awesome. Thank you! I was starting to get worried

You may still need to be worried. They will spread over everything.