New Setup, Live Sand, Intresting Critter

[Nibejeebies]

So My tank has been set up about two weeks now and I went with black Live Sand for the bottom substrate. Threw in some live rocks upon set up and was sitting on the couch and noticed a little guy in the sand. I am hoping that some one can tell me if hes good or bad and what he is... I really don't know how other to identify him.
I am new to the salt water tanks, but not to aquariums.
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[saltyfilmfolks]

amphipod . A good thing.

http://www.lionfishlair.com/hitchhiker.shtml

 

[Nibejeebies]

Thank you Saltyfilmfolks Ive saved that site and read almost through their checkoff. Thank you again.