Crook of Rao

In the World of Greyhawk campaign setting for the Dungeons & Dragons role-playing game, the Crook of Rao is an artifact, appearing as a shepherd's crook, which has been in the possession of Canon Hazen of Veluna since 585 CY, when he acquired it from Drax of Rel Astra. The crook was used to remove most of the demons from the Flanaess in a ceremony called the Striking of the Crook, performed by a select number of Oerth's most powerful clerics and wizards in Coldeven of 586. The resulting event is known as the Flight of Fiends.

The Crook in Living Greyhawk
In events that take place in the Living Greyhawk campaign, it is revealed that three Raoan priests were tricked into betraying Canon Hazen by accepting magical curses which transcribed the true names of 101 demons onto their skin in the forms of magical tattoos. These 303 demons were not banished. It is further revealed that most of the powerful demons left of their own accord to make the ceremony appear more successful than it truly was. In the aftermath, the Canon has rarely been seen due to his weakened condition and the Crook has lost most of its power.