Apart from the biography/filmography/discography, which have already been done, we should note his sound.
Someone once told me that Tom Waits was once shot in the throat as a bystander in a bar fight gone bad. This may well be utter myth. He said in an interview that he got his from trying to have a voice like his uncle, who had had botched throat surgery. Either one may serve as a fitting explanation if anyone ever asked. Most people can't do impressions unless they have a particularly inspired cold.
Waits has hugely wide-ranging influences. He also uses a range of instruments that reminds me of the experimental improv sessions in MPZ, only more listenable. He employs everything from marimba to bar piano to beat-up boxsprings, trombones, talking drums, stolen dreams, Burroughs' voice and the mysterious bone machine.
You know the phrase "you the man"? Tom Waits reclaims the term The Man for his own sweet rough clinkety-clankety inscrutable self.