Hogwarts witch wearing a big hat

This Male Professor was teaching at Hogwarts School of Witchcraft and Wizardry from 1991 to 1993 at least and was always seen at Professor Dumbledore's side.

Career at Hogwarts
This teacher was in a career of teaching at Hogwarts School of Witchcraft and Wizardry by at least 1991. He was seen at Professor Dumbledore's left hand side while Harry Potter and his classmates were being  Sorted. He later attended the Gryffindor vs.  Slytherin Quidditch game, sat by the Headmaster again. Later that year, the Professor's fellow colleague, Quirinus Quirrell, was revealed to be after the Philosopher's Stone which was hidden inside the school. Apparently, this teacher was not chosen to protect the Philosopher's Stone Chambers. He was also seen at the End-of-Term Feast, in the same seat as last time, and watched as Gryffindor won the House Cup.

At the next year's Gryffindor vs.  Slytherin match, the Professor was once again seen by  Professor Dumbledore in one of the towers and he applauded as Gryffindor scored. His seat in the End-of-Term Feast had been taken by Madam Pomfrey.

Behind the Scenes

 * This character has appeared in two film adaptions and is the only unidentified teacher to watch two Quidditch matches.
 * Since this Professor was seen in only the first and  second films, it is possible that he was  Professor Silvanus Kettleburn, who taught Care of Magical Creatures until he was replaced by Rubeus Hagrid.

Appearances

 * Harry Potter and the Philosopher's Stone (film) (first appearance)
 * Harry Potter and the Chamber of Secrets (film) (last appearance)