Help ID this growth on my torch

[HeiHei29er]

I'm quickly losing my torch and may just pull it tomorrow.

There is an unknown growth on the side of my torch. I originally thought it was a new head popping out, but I don't think so anymore.

This torch started as a two branch with a head at each end.


However, I lost the left side branch shortly after this photo. There was a growth of some kind at the base of the coral (you can barely see it as a dark spot with white edges just above where it's mounted to the rock), and head just wilted away over a 4-5 day period until there was nothing left. I split the branches and remounted the right side because it was still healthy.

I noticed this growth over the last 4-5 weeks. It started about the size of a pencil eraser and is now about the size of a dime. I've also seen it "retract" or close a couple of times when disturbed. Here's a picture of the torch now and a close up of the growth.

Any ideas?

Thanks in advance.