Ogrek

A Morok commander was a Morok officer stationed on Xeros, and was the second in command of the Space Museum.

He and another guard discovered Vicki Pallister, Barbara Wright, Dako and Sita outside the museum and shot and killed Sita. He and the guard then took them to Lobos' office.

When the Xerons started a revolution, the commander went to Lobos' office. He and Lobos decided to escape Xeros in a spaceship, but then decided that they should kill the First Doctor and his friends before they leave. The commander and Lobos prepared to shoot the Doctor and his friends, but Tor and four other rebels entered the office and shot and killed the commander and Lobos. (TV: The Space Museum)

Behind the scenes
He is given the name of Ogrek in the novelisation.