coral id please

[Lwedin]

I was thinking this was a frohspawn, but it doesn't look like what I find on the internet

 

[Udest]

that looks like a star polyp of some sort dose it have a purple base mat underneath it ?

 

[Lwedin]

Yes it does.

 

[Udest]

most likely green star polyp then besufe to isolate it from your main rockwork on an island it might decide to take over.

 

[Phildago]

The dreaded green star polyp.

May god be with you