"Killer Queen" is a song by the British rock band Queen. Written by pianist and lead singer Freddie Mercury, it was featured on their 1974 album Sheer Heart Attack, and also appears on the band's compilation album,Greatest Hits. When released as a single, "Killer Queen" was Queen's breakthrough hit, reaching number two in the United Kingdom and number 12 in the United States. It was released as a double A-side in the UK, the US and Canada (where it reached number 15 in the RPM 100 national singles chart), with the song "Flick of the Wrist". In 1986, it was featured as the B-side to "Who Wants to Live Forever". The song marked a departure from the heavier material of the band's first two albums, as well as the beginning of a more stylistically diverse approach in songwriting. At the same time, "Killer Queen" retained the essence of Queen's trademark sound, particularly in its meticulous vocal harmonies. Mercury commented that he wrote the lyrics before the melody and music, whereas he would typically do the opposite.