Scraps is a young homeless boy, who's inherently messy nature and playful personality drove his parents figuratively crazy. They dropped him off at the nearest place they could find, where the owner of the junkyard took pity on him and gave him a bed to sleep in. Still in the junkyard, obviously. 

As mentioned before, Scraps is a inherently playful and messy person. He's also a merchant, in that he sells scrap metal and nifty little  knickknacks from the junkyard to anyone who asks. For ten dollars an item, of course. In  terms of his voice, I'd imagine something laid back and somewhat high pitched, but not really all that higher pitched. Try to aim for a Phil Solomon as Craig Williams type of voice.