Drahvin One was one of the cloned, semi-intelligent Drahvin soldiers serving under Maaga, who became stranded on the disintegrating planet in Galaxy 4. She was sent with Drahvin Two to bring the First Doctor, Steven Taylor and Vicki Pallister to their ship. They disabled the Chumbley escorting them with a magnetic mesh but failed to retrieve it and were forced to retreat with the three travellers when more Chumblies approached.
Once back at the ship, Drahvin One joined the other Drahvins in driving off a Chumbley which had brought a message from the Rills. She and Drahvin Two were chastised by Maaga for losing the mesh. Having gone out on patrol with the other Drahvin soldiers, they returned in time to put an end to a fight between Steven and Maaga and to threaten Vicki's life to force the Doctor to reveal the planet would destroy itself in two dawns' time.
Steven nearly tricked her into giving him her gun and stealing Maaga's for herself by suggesting Maaga would be pleased. She expressed confusion that they did not go out on patrol at the usual time and at Maaga's insistence that the Doctor and Vicki would return for Steven. On solo patrol, she encountered the Doctor, Vicki and a group of Chumblies. She was not convinced by their claims of friendship and fired on the Chumblies but was overpowered. She was imprisoned in the spaceship with the other Drahvins when Steven was rescued.
After the Chumbley on guard had been destroyed by Drahvin Three, Drahvin One joined Maaga and Drahvin Two in attacking the Rill ship to try to capture it before the planet's destruction. They were defeated by the Chumblies and watched in horror as the ship took off without them. Maaga decided to hijack the Doctor's TARDIS instead but they were held back by the remaining Chumbley and ultimately perished in the planet's destruction. (TV: Galaxy 4)