From Discworld & Terry Pratchett Wiki
|Books||Hogfather, The Truth|
A member of the Canting Crew of Ankh-Morpork. He has no legs, and it is hinted that he may be deformed in other ways. It is stated that anyone looking at him for too long gets the distinct impression that they are upside-down. Because of his missing legs, his primary form of transportation is a four-wheeled cart. While Arnold is completely legless, he nevertheless does have a boot, which he holds on the end of a wooden pole. This is very handy for sticking in closing doors and hitting, sorry, kicking people with. Arnold's boot gives him a sizable advantage in bar fights, along with his lack of legs. In a free-for-all fight, a man with good teeth at groin height has it all his own way.
Arnold's primary begging technique is to grab people by the legs and ask, "Have you got change for a penny?", usually profiting from the inevitable confusion. (After all, look at all the potential sub-divisions of a penny, which would tax any mind)