Tiffany Aching is a fictional character in Terry Pratchett's satirical Discworld series of fantasy novels. Her name in Nac Mac Feegle is Tir-far-thóinn or "Land Under Wave".Tiffany is a trainee witch whose growth into her job forms one of the many arcs in the Discworld series. She is the main character in The Wee Free Men, A Hat Full of Sky, Wintersmith, I Shall Wear Midnight and The Shepherd's Crown .