Carcass was formed as a D-beat band by guitarist Bill Steer together with drummer Ken Owen in 1985 under the name Disattack. After releasing a demo entitled A Bomb Drops ... in 1986, Paul (bassist) and Andrew Pek (vocalist) of Disattack left the band and were replaced by vocalist Sanjiv and bassist Jeff Walker, formerly guitarist and vocalist of the Electro Hippies. At about the same time, Bill Steer joined Napalm Death (replacing Justin Broadrick) and recorded the second side of what became Napalm Death's first album, Scum. Walker also designed the cover art for Scum.
Disattack then changed its name to Carcass. In April 1987, they recorded the Flesh Ripping Sonic Torment demo, the only Carcass recording featuring vocalist Sanjiv, who left shortly after. Walker, Steer and Owen shared vocal duties for the debut album, which was done in only four days. Despite the primitive production values of Carcass's debut Reek of Putrefaction, with which the band was very displeased, it became a favourite of Radio 1 legend John Peel. Due to his interest, they were asked to participate in their first Peel Session in 1989, where they debuted new material for their second album. The Peel Session was released as an EP with the band members adopting pseudonyms: K. Grumegargler, J. Offalmangler, and W.G. Thorax Embalmer. Also that year, Steer and Walker appeared as members of Lister's fictional band Smeg and the Heads in an episode of Red Dwarf.