New sps frag bug?

[Maxxingout]

Wonder if anyone might be able to help out? I bought some new frags 4 days ago. I dipped them in Bayers @ 10ml/4oz ratio for 10min. All of them seem to be doing fine minus one. I noticed yesterday that on the back side of this sps (sorry not sure what it is, still new to sps) something resembling algae was growing. From my pics it looks like something was on this frag when I got it but didn't notice then. I rotated the frag to try and take better zoomed in shots and noticed something else too. It looks like some type of worm or bug? If you look at the pics you can see the brown dome like thing with arms/claw type things on the sides. You can see that in one shot they're curled but in the other they're straightened out. Anyone have a clue as to what it might be? The algae stuff looks like it might be spreading but I'm not sure? This is the only frag with this problem. I have all the frags on the sand bed acclimating right now.

 

[oscarinw]

Although I can't seem to figure out what it is, I would definitely recommend taking it off and cleaning it as soon as possible.

 

[Maxxingout]

I took the frag out and tried grabbing whatever it was. It retracted into the hole it created. It's been eating the coral and the decaying flesh was having algae growing on it. I basically dug it out while squashing it at the same time. Tried cleaning it and dipped it in Bayers again. Now it's a,waiting game.