Master Beta was a government scientist who had wanted to live in London and write musicals, but due to constant harranguing by his mother got a job with the government.
For unspecified reasons he had a betamax videotape player in his forehead, from which he could play tapes with such titles as Villainous Gloat, Diabolical Laughter Vol 3, Belittle Hero's Efforts and Explanation of Evil Plan.
He created a fleet of clockwork pterodactyls, but this did not impress his mother. He ended up killing her by beating her to death with a copy of the Radio Times, only for her to come back as a ghost, the Wailing Widow of Wemberley Common.
To escape from her, he took to living in an underground laboratory beneath a Little Eater service station where he worked on government schemes.
Upon learning that his mother had finally been exorcised, he destroyed the controller of the copper army but was killed by Shelley before he could reverse the assembly line and send the coppers back into the furnace.