Garvo

Garvo was a musician on the asteroid of Stanalan. His music made Drexxons dance. He kept one of the creatures on a leash lest it run away. Amy Pond once took off the leash just to see what would happen and it seemed to upset Garvo. She soon realised that Garvo was being controlled by the beast. He became mad and helped free more Drexxons from the chamber in the asteroid. He finally woke up after the Drexxons were destroyed and the link broken. (NSA: Death Riders)