Need ID

I need an ID on this please. I think it came from Reef Splash.

 

It's been growing pretty fast. It's got a mouth and is quickly covering the old skelton where it was dying off. No one have any idea?

 

Looks like a perfect square of algae, nice and green !!!!!!!!!!!

 

Is it soft or stony? Does it have polyps or tentacles that come out periodically?

 

It is an Open Brain coral

 

Fisher that is green coraline

Slugg thank you for the ID!

 

I looked it up in the Marti Coral Identification Book and it says that it is clearly a "round green thing with bumps all over it".

 

Schiller that's what I've been calling it too! That must be a very good book, what a coincidence!