The Collector

The Collector was a Usurian who, aided by his human assistant Hade, oversaw operations in Megropolis One on Pluto. The Usurians' Company had, by this time, made Pluto into a world inhabited by humans who lived in cities lit by artificial suns. The Collector, who in his native form resembled kelp, maintained a humanoid form on Pluto. When the Fourth Doctor reprogrammed the Company computer to apply a 2% growth tax, indexed, the loss of profits so upset the Collector that he reverted to his native form and was imprisoned with a champagne cork. (DW: The Sun Makers)