New Setup, is this a pest?

[ScubaSteve]

It almost looks like a nem I have in my tank (mine is bright green/yellow). I have no idea what mine is (someone suggested a type of rock anemone) but I know for certain is is not a mojano or aptasia and hasn't been a pest yet. I've even started feeding mine and he's growing ino something pretty snazzy (he's VERY flourescent).

If you know is not a zoanthid of some sort and you're not sure what it is yet, just isolated it and keep an eye on it, might be something cool. I'm glad I didn't wipe mine out when I went aptasia and mojano hunting when I first got my rock.