Qixotl

Mr  was a humanoid of undetermined species. He held an auction on Earth in the late 21st century. The sole item for sale was the Relic, whose existence he learned of while stranded on Dronid. During the course of the auction, Qixotl was killed by the Krotons, but recorporated by the Celestis in exchange for the Relic. The Eighth Doctor recognised him as someone who betrayed him in a prior incarnation. (PROSE: Alien Bodies)