ID help please?

[Piper1]

This one thing has been in my tank since the I put my live rock in about 3 months ago. It has grown in size and color. It has not multiplied or spread. Just the one head and stalk. At first I thought it might be aptasia, but as it gotten more color and grown out more, I thought maybe it is a button polyp or something? The peppermint shrimp don't touch it. Any ideas? thanks

 

[LukFox]

Yeah it's just a polyp. They sometimes hitchhike on live rock. It should spread in time, but it's not a pest.

 

[richofoz]

I wish my aptasia grew up into something cool!!

Could be some kind of zoanthid?

 

[IslandCrow]

Yes, that looks like a zoanthid. They're a bit annoying if you don't want them, since they often times do grow and multiply quickly and they're very difficult to kill. Otherwise, pretty harmless.

 

[Frick-n-Frags]

Protopalythoa, "button polyp"

Protopaly's don't grow from a big thick mat like Palythoas.