Ziigy was one of Bowie's most famous alter egos, even releasing an album The Rise and Fall of Ziggy Stardust and the Spiders from Mars in 1972, which was about, well, the rise and fall of Ziggy Stardust.
He also reportedly had another alter ego who went by the name of The Thin White Duke, who reportedly lived off red peppers, cocaine and milk. This particular persona has been described as "a mad aristocrat" and "an amoral zombie", with Bowie saying that he was a "nasty character indeed".