Who is Tollie from The Game and what is their importance?

Tollie is Hayley's youngest male cousin. He is described as temperamental and mischievous. Tollie takes an immediate dislike to Hayley when she arrives in Ireland, and he often cheats at the game, threatening to tell Uncle Jolyon if he doesn't get his own way. In Greek mythology, Autolycus (Tollie) is the son of Mercury (Mercer). He is a trickster and thief and quite ill-tempered.