Crab info
 

So I remember seeing this kind of crab in my tank about a year ago and thought I got rid of him but as I was doing my weekly night viewing I seen him again.. And he was pretty big.. About the size of a toonie.

Looks like this.
http://www.flmnh.ufl.edu/reefs/guami...e/Images/1.jpg
This is an image I found off the internet but he looks like this. Red little eyes, same shape and grey.

What kind of info can anyone tell me about him.. I have never had any issues from him as far as I can tell.

http://www.chucksaddiction.com/hitchcrabs.html
Also looks like the guy on the top here

Link did not work for me... but red eyes are a bad sign.