Thunderbeak was a female barn owl, the wife of Stonehead McGurney and the mother of two daughters and two sons. She was described as fierce and lived in northwest Mossflower Woods. Thunderbeak met Mariel Gullwhacker, Dandin, Durry Quill and Tarquin after Stonehead had saved them from Flitchaye. Thunderbeak was a minor character, little else is known.