He is the chief stagehand for the theatre who claims to have seen the Opera Ghost. In the novel he is the one to first describe Erik, saying, "He is extraordinarily thin and his dress-coat hangs on a skeleton frame. His eyes are so deep that you can hardly see the fixed pupils. You just see two big black holes, as in a dead man's skull. His skin, which is stretched across his bones like a drumhead, is not white, but a nasty yellow. His nose is so little worth talking about that you can't see it side-face; and the absence of that nose is a horrible thing to look at. All the hair he has is three or four long dark locks on his forehead and behind his ears."
In the first chapter he was found to be hanged in the third cellar between a flat and a set piece from Le roi de Lahore, right next to the entrance to the Phantom's torture chamber.
In Andrew Lloyd Webber's 1986 stage version, Buquet describes the Phantom's appearance to the ballet chorus and demonstrates the way to counter his "magical lasso" (the Punjab lasso, the Phantom's weapon for strangling victims). Cautioned by Madame Giry against speaking out, he is later found strangled and hanging from the stage rafters during a performance, throwing the audience into chaos.
In Nicholas Meyer's novel The Canary Trainer, Erik kills him as punishment for Buquet declaring his love to Christine Daaé. Irene Adler, currently performing Carmen at the Palais Garnier, hires Sherlock Holmes to investigate his death, beginning the series of events that pits Holmes against Erik.