hammer coral regrowing from empty skeleton

[lnk89]

So about 8 months ago I bought 2 hammer coral frags. One has done really well but the other started to die within a couple of weeks. Eventually all that was left of the hammer coral was a empty white skeleton. Since I am new to this saltwater keeping thing I decided to leave it in the tank to see what happens. And now it kinda looks like something is growing on it again. Is this possible?

I see something green sticking out the side of the skeleton and a bit of green at the bottom near the back of the skeleton. I have only noticed this within the last few weeks.

Has the coral started to regrow or has the other hammer coral spread?

Attached a crappy cell phone pic of the possible regrowth.