Billy (Delta and the Bannermen)
Billy was a mechanic at Shangri-La, he was also the lead singer of The Lorells. He owned a motorbike called The Vincent.
Biography
At Shangri-La
  Billy was a childhood friend of Rachel Defwydd who, unknown to him, had a crush on him. He built a speaker system with spare parts from the war. When the Chimeron, Delta, arrived at the camp Billy took a shine to her and sang Why Do Fools Fall in Love in dedication to her. She told him of the Bannermen and he helped her look after the Chimeron Princess.
Against the Bannermen
He took Delta and the child to a secluded spot by a river where they rested. The Doctor took the trio to stay with Goronwy, whilst there Billy stole some Chimeron Jelly from Delta. She caught him eating it and he told her he wanted to become a Chimeron so he could come with her. He helped the Doctor set up his speaker system so that the Chimeron Princess could send the Bannermen into disarray with her singing.
Leaving Earth
The Bannermen were restrained and tied up aboard the Bannerman craft that Delta stole. By this time Billy was fully transformed, his skin a silvery colour. The Doctor noted his rash behaviour but recognised that love was not rational. He told Ray to take care of the Vincent as he boarded the Bannerman craft. He then left with Delta and the Princess, headed for the brood planet. (DW: Delta and the Bannermen)
