ID on hitchhiker?

[KellyPug]

I've had this guy for awhile now. He came on the back of a couple rhodactis shrooms I purchased. I know he eats mysis shrimp when I target feed or when he happens to catch some.

Anybody know what he is? Thanks in advance!

http://i18.photobucket.com/albums/b136/kellypug/Fish%20Tank/whatIsThis.jpg