Lovely. I've had him too long to return... he's (she's?) *very* light-sensitive, dives under a rock when the light goes on, but I'll try to get a picture.
Did I read correctly upthread that you got it at Walmart? You almost certainly have a common pleco. There are a number of different pleco species sold under the name "common" pleco...and the smallest of them grows to at least twelve inches. Many of them grow to over two feet.
I'm sorry that you were so badly misled, but you very definitely need to either return the pleco or get a SIGNIFICANTLY larger tank. Full-grown commons need, at an absolute minimum, a 90 gallon tank. They really should be in 125 gallons or more.
Again, I'm so sorry that you were sold such an inappropriate fish for your tank, but sadly this sort of thing happens all the time. Try to return the fish to Walmart. If they don't let you return it, your best option is to go to the nearest aquatics store (Live Fish Store, or LFS) and explain to them what happened. There's a good chance they'll help you out, and even if they won't give you any credit for the pleco, they'll at least take it off your hands.
Unfortunately, Walmart has an incredibly poor reputation for their live fish sales, and even more unfortunately, this poor reputation is one they earned and well deserve. They are notorious for housing the fish in heinous conditions, and consistently (and worse, often knowingly) selling inappropriate fish to unsuspecting newcomers to the hobby.
Just as a warning, Walmart is by no means the only retail outlet to maintain such practices. Pet shops like Petco and Petsmart are often equally bad. They provide little or no training about fish care and upkeep for their employees. Some of them will make the effort and become self-educated, responsible salespeople who can provide a wealth of helpful information. Others are simply salespeople, and the sad fact is that they can and will tell you anything to make a sale. It is left to you to do the legwork of research before you head to the store.
If you want a bottom dweller for your tank and you like the look of the pleco, a Clown Pleco would be an appropriate choice for a 10 gallon. They stay quite small, and they won't outgrow your tank. If you'd rather have something entirely different, you can look around online or in a shop, then come back here and list the fish you saw that you like. There are a ton of friendly, knowledgeable people around here who will help you out with planning a nice stock for your tank.