Hogwarts wizard in the Middle Courtyard

An Unidentified male teacher worked on Hogwarts School of Witchcraft and Wizardry. In 1991, he helped some students with homework, including Hermione Granger on the Transfiguration Courtyard. He also appeared in the Great Hall and at some Quidditch-maches in the schoolyears 1991–1992, and 1992–1993.

Behind the Scenes
This professor could be Silvanus Kettleburn, a ex-teacher of Care of Magical Creatures.

Appearances
Harry Potter and the Philosopher's Stone (film)

Harry Potter and the Chamber of Secrets (film)