what is this? newbie Zoanthid Question

[BlueAbyss]

+1 Dichtyota... mine is iridescent blue though Anyhow, I just pluck the algae off, I have some wiry stuff that is fairly aggressive but I find if you remove it relatively aggressively it goes away over time (or at least doesn't grow back as thick). The Dichtyota you can just pluck the leaves off areas where you don't want it, it grows slowly enough if your plan isn't to eradicate it completely.