Jinko was an eighteen-foot-tall cyborg life form made entirely out of customised junk metal. He was a scrap merchant who made deals with dodgy vehicles.
Jinko sold a Zocci friend of the Eighth Doctor's a dodgy planetary hopper, which crashed on Carolian IV. Jinko refused to refund the Zocci's grotzits, so the Doctor used his sonic screwdriver to reduce Jinko's merchandise to molten metal. Jinko held a grudge against the Doctor ever since.
One hundred years later, Jinko took revenge on the Ninth Doctor by stealing a red bicycle intended for a twelve-year-old Rose Tyler. He hired three Elians to help him. The Doctor used his sonic screwdriver on the junk pile in Jinko's junk yard, making it collapse on Jinko, crushing him. (PROSE: The Red Bicycle)