Text quoted from The New Discworld Companion.

Swires, Buggy. A gnome, first met during the events of The Light Fantastic. He lived in a mushroom with a red-and-white spotted cap and little doors and windows. He is six inches high, picks his nose and looks like someone who smells like someone who lives in a mushroom. He is now a corporal in the Ankh-Morpork City Watch. He has an inbuilt resistance to rules - not just to the law, but also to those invisible rules such as 'Do not attempt to eat this giraffe'.