Maleans were a shape-changing species that focused on perfection.
Individual Maleans were not supposed to have empathy or affection for others, and those did so were considered to be mutants and were destroyed. (PROSE: The Golden Door) The Seventh Doctor pointed out, however, that the mutations were inevitable as their DNA was so malleable. (PROSE: Playback)
In the 20th century, the Maleans aided the Nazis in Europe during World War II as part of a racial purity program, but Mykloz, now their American agent and slowly mutating himself, failed to keep the United States out of the war as he was instructed. (PROSE: Playback)