I have had my tank for about 5 months now. I have live rock a clown, a rassy, a zebra eel and some coral. Recently I was trying to feed my eel and while I had his food on a stick and something came out of the rock and took it from me...needless to say, freaked me out. I have been trying to identify it and the only thing that it comes close to is a mantis shrimp. The only thing is it doesn't make any noise and I can't really tell if it has tentacles. I only have a video of it so I took some screen shots of it so I could post it. The quality is kind of poor but for now its all I have. It is purple blueish in color and lives in this rock and I have never really seen it out and about only lurking in the hole. Any help or suggestions would be great.