Hey Nightryder, hard to tell from the pic, but it's probably a type of algea, or sponge. Could also be a piece of soft coral, don't think it would be a LPS
, being transparent. Not sure about a soft coral starting off transparent either, but it sounds possible.
, it's most likely just algea or a sponge. So many things can sprout up out of rock it's amazing. I've had a Zoo colony for like 6+ years( dragon eyes) and its just now sprouting a feathery- orange type of algea, and it's pretty cool looking, luckily.
I would just keep an eye on it for changes, it shouldn't hurt anything, and if you don't like the looks of it, you can probably just cut it off the rock.