Allan Thiel is an agent of the Wizard Justice Department who was placed undercover as a custodian and groundskeeper at Charmbridge Academy, assistant to Ben Journey. He wears a scraggly goatee and an earring. Journey regarded him as largely incompetent and lazy, since he only seemed capable of doing simple tasks that require repeated instructions.
In May 2008, Alexandra Quick was assigned detention with Thiel degnoming the Academy campus, and in preparation for the arrival of Governor-General Hucksteen, Thiel was instructed to clean out the Registrar's Office. When Quick offered to do the job for him, he became suspicious of her ulterior motives, and ordered her to continue degnoming the Academy campus instead.
He later caught Quick and Anna Chu breaking into the Registrar's Office, but was disarmed and stunned by the pair. He was assigned to escort Alex to her dorm room and make sure that Quick did not leave, but failed to stop her from leaving through the second-story window.
He shares his surname with Civil War spy George H. Thiel.