Billy (Delta and the Bannermen)

From Tardis Wiki, the free Doctor Who reference

Billy was the mechanic of Shangri-La, and the lead singer of the Lorells. He fell in love with Delta, and helped the Doctor protect her from Gavrok and the Bannermen. He ingested Chimeron Jelly and began mutating into a Chimeron, and after the Bannermen were defeated, he left Earth with Delta to help her repopulate Chumeria. Before leaving, he left Ray (who had had a crush on him) his motorcycle. (DW: Delta and the Bannermen)