Who is Daggy and Snowy from The Last Continent: A Discworld Novel and what is their importance?

Daggy and snowy are a gang boss in Dijabringabeeralong, a tiny town on the last continent of Fourecks, Daggy prepares the hapless protagonist, Rincewind the Wizzard, for a sheep-shearing contest with the experienced locals. In a drunken stupor, Rincewind has issued a challenge and is sure to lose. He is saved from failure by an incarnation of The Trickster as a talking Ram, who convinces the sheep to cooperate. When Rincewind wins, he is sent out of town by the terrified locals.