"Mansize Rooster" is a song by Supergrass, released as the second single from their debut album I Should Coco. It reached number 20 in the UK Singles Chart, remaining on the chart for three weeks. Like its predecessor "Caught by the Fuzz", "Mansize Rooster" was originally limited to 500 copies as a 7-inch vinyl-only, Backbeat Records release, although pressings are believed to have been made since. The B-side remained to be "Sitting Up Straight", but the songs sound slightly different and have different runtimes to their present-day versions. The Backbeat vinyl it was primarily issued on was also green. The song is used in the movie Casper: A Spirited Beginning and is included in its soundtrack.