it looks like it may be one of the various species dubbed "Tire-Track" eels. I have one that is almost black with beautiful tan markings the contrast is wonderful. They are considered to be ok in a "community" setting, so long as the fish aren't small enough to fit in their mouth. They to get to like 1 1/2 feet long, so you may be getting a much larger tank in your future.
P.S.- Just a tip. I found a great way to feed them. I put some frozen brine shrimp in the bubble of a turkey baster that has the tip cut off to where the eel can enter it, and I place the whole thing in the tank, after defrosting in tank water of course.