This chapter considers the work of Marcel Duchamp, and particularly his 1959 work With MyTongue in My Cheek. Focusing on the years 1958–64, the chapter considers how Duchamp’s work underwent critical reappraisal on both sides of the Atlantic for the way it transformed the art object and ideas about art. Duchamp deployed deconstructive humor and irony to engage the spectator in his work, which is evident in Tongue in Cheek on several levels, while also revealing the workings of the art market. Specifically, this chapter theorizes Duchamp’s deconstruction of identity, bringing together, seemingly intuitively, the three basic identity supports that are the proper name, the portrait, and the imprint. The portrait is drawn with a pencil, the cheek is a molded imprint of the artist’s, and the work is signed Tongue in Cheek, Marcel Duchamp, 1959.