Like the Harry Potter series, there are many interesting words created by the author for Guardians of Ga'Hoole. Some of them are hagsfiend, an ugly, dangerous crow-like creature that lived in King Hoole's time, Glaumora, the owl heaven, and even bonk, used to describe a very hot coal! To see more words from the world of Ga'Hoole, have a look at Ga'Hoole Vocabulary by LegendTeller. It's in my Guardians of Ga'Hoole fanfiction list.