Strange looking fellows (Friend or Foe)

[4n2xtacy]

So I got this zoa rock from my LFS a few weeks ago. Dipped it in coral dip and then freshwater dip. Brushed it off thoroughly and after a thorough inspection, put it in the tank. The next day I saw these strange looking transparent hair looking things and thought it was probably some kind of algae so I tried to clean it off with my fingers. It retracted immediately. I never saw it again until last night I saw three of them in 3 locations of the same rock. They seem to come out only at night when the light goes off. Below is a picture of it. I know for sure it's not aptaisia because if u look closely you see it has tentacles with some kinda tip. Please does anyone know what this is,should I be worried,are they friends or foes?

 

[Crabs McJones]

From what I can tell, it looks like a ball anemone. Generally harmless

 

[reef lover]

+1

 

[4n2xtacy]

From what I can tell, it looks like a ball anemone. Generally harmless

I looked it up, it does look like a ball anemone and they harmless like u said. Thanks. I feel much better now.