Could this hitchhiker be a coral?

[marcingo]

Hello- I posted previously regarding this matter and people thought what I have found might be a apstasia or zoanthid. Here is an update on the characteristics of this thing.

Basically when it closes up completely at night it looks exactly like a single zoo polyp. Now when its open its has tentacles which look almost identical to hammer coral- there is a small center on this creature that has nothing in it but other than that the tentacles cover the whole area of the polyp except for a very small part that is empty. The very tips (hammer shaped) seem to be coloring up and are a very faint orange. The remainder of the tentacles are brown. This thing seems to be very sensitive- I walk near the tank and notice it reacts.

Also from previous observations- when I would turn the light on before at night rather than the polyp being closed it was open but the tentacles were deflated to hairlike thickness.

This creature is also growing very fast its starting to fill up the hole it lives in. But it doesnt seem to be making new polyps like one would expect a zoanthid or paly to do.

Any idea what this could be? Also my tank has been running for just over a month and this creature just appeared about 4 or 5 days ago.

Thanks.

PS I tried to take a picture but my camera doesnt seem to be able to focus in on this creature so no I cannot get a picture of this.