Sexuality was not just an underlying theme in Giger’s work, nor was it confined to symbolic references to sexual organs and reproduction. He made numerous drawings and paintings depicting explicit sexual activity, often involving several figures, unusual positions and elements of fetishism or domination. In some the encounters are presented relatively directly; in others human bodies become entangled with machinery, grotesque anatomy and disturbing forms of transformation. Giger’s sexual imagery is often interpreted through the language of the unconscious and his recurring nightmares, but in many of the more conventional drawings sexuality is a sustained and explicit focus.

In his trademark airbrush paintings Giger developed a distinctive visual vocabulary of phallic shapes, vaginal openings, exposed flesh and mechanical structures. He was conscious of the sexual associations of this imagery, although he resisted the idea that every suggestive form required a fixed interpretation. In a 1994 interview with Steven Cerio, he remarked that long objects could be read as penises and hollow forms as vaginas, while observing that viewers sometimes found sexual meanings he had not consciously intended. He described the figures in his work as often representing people he admired, particularly beautiful women, and said that he liked creating faces expressing ecstasy. He also distinguished between violence and sexual play, suggesting that imagery which appeared violent to others could be understood differently.

Among the most striking are works from his Landscape series, in which organic forms, bodily structures and explicit sexual references are incorporated into strange, often unsettling compositions. The landscapes range from images in which the erotic content is relatively oblique, with forms that suggest flesh, bodily openings and interlocking limbs, to works of extraordinary directness. Landscape XX, also known as Penis Landscape, is perhaps the best-known example. Its repeated interlocking genital forms, arranged in a dense, almost geological pattern, make the sexual subject impossible to overlook. This painting became notorious when reproduced as a poster accompanying the Dead Kennedys’ 1985 album Frankenchrist. The ensuing controversy, which led to the prosecution of the band’s singer, Jello Biafra, brought Giger’s work into the centre of a debate about censorship and the limits of artistic expression.