the american "march of the pigs" cd single contains two mixes of the title track, two remixes of its fellow "the downward spiral" track "reptile," and "a violet fluid," a non-album instrumental track. in the uk, the single was released as a two-disc (each sold separately) cd single, adding a censored radio edit of "march of the pigs" and "big man with a gun" from "the downward spiral". the disc art for this single features a curled-up millipede, an image that was later used on the cover of the single "closer".