Reefer's Dreams

I have absolutely no idea what this creature is. I got him with the same piece of live rock that has the coral on it. He is a very dark red, maybe even bordering on purple, and he has little light spots on the end of his antenna or whatever they are. He almost looks like a snail that has no shell. If anyone knows what this is please let me know.
pic of the animal
pic 2
pic 3
pic 4

please looks at all the pictures to get an understanding of what it is.