Earll was a human female who served in the military of the Galactic Empire. By the fifteenth year of the Age of the Empire, she held the rank of commander. Around that time, Earll receptioned a distress call sent by Nadea Tural of the Imperial Senate, but it transpired that the senator had already been rescued by a group of anti-Empire insurgents from Lothal. Along with a squad of stormtroopers, Earll boarded the rebels' ship, the Ghost, and ordered the immediate execution of its crew. Senator Tural, who had demanded a fair trial for the rebels, interposed herself when Earll's troopers were about to fire, allowing the Spectres to get the upper hand. The Imperial commander herself was shot and stunned by Hera Syndulla, the captain of the Ghost.
Earll was a tall, thin woman with pale sallow skin, ice blue eyes, and short black hair. She was ruthless and unsympathetic, willing to execute the Ghost crew despite the protests of Senator Tural. She appeared more competent than most Imperials encountered by the Ghost crew, personally subduing Sabine Wren and Ezra Bridger while her squad successfully captured the others. Despite succeeding in capturing them, she failed to execute them nonetheless.