Multiplying

[David Grubb]

I was old it is a mushroom but dont know really anything about it, there was just 2 now I'm up to 7 of them. Is that good bad and what kind is it

 

[Retro Reefer]

Not sure of the exact variety but its not uncommon for some of them to reproduce in pelage like proportions. I would try to keep them isolated on that rock. Another issue that may arise is some of them can be pretty toxic to other corals Via chemical warfare.