If you mean the green 'wavy one' centre left then I believe it's called an Australian Duncan Coral.
I've had it since June 2016 and is has grown considerably. I would like to frag it but I'm a little scared of touching it as cutting it into pieces makes me a little nervous. If anyone here can tell me how to do it I'm all ears ??
Yes that one....if that is a Duncan that is the largest I have ever seen! Very nice!
I wish I was able to offer something in regards to fragging but I haven't made it there yet!