Newbie needs an ID on this Polyp? Coral?

[amonk]

Hi all thanks for taking time to view this post.

First off I am relatively new to saltwater and therefore this is my first live rock. I have been pulled in hook line and sinker and I am now completely addicted to trying to find new things growing on it.

I noticed this a week ago and now it seems to be spreading unless the others around it are a different type

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[bribo12]

Could be corynactis or the ball anemone. They are super cool and kinda rare. However, it's kind of hard to tell from the pic. Try looking those up though.

 

[amonk]

I am currently looking it up and it does look similar. Next question is should I keep it? Will it harm any of my fish or take over my small tank?

 

[bribo12]

If you're not planning on keeping corals, I'd keep it. They are actually pretty and will not harm your fish.

 

[amonk]

Trying to take a little closer shot.