Something one the live rock

[T-hawk]

Got two small pieces of live rock to help seed the dry rock. Just noticed something on it and need help identifying what is on it and whether I should be concerned. It came from a shop, it was in the sump of a coral frag tank. Thanks for any help.

 

[Tahoe61]

Corynactis.

 

[T-hawk]

Doing some research on here and elsewhere, sounds like if I keep parameters in check then I can leave it be.