Songfacts®:

• The title refers to the female behind, but also to the low, bass-heavy sound in this song. Nigel Tufnel of Spinal Tap says, "Historically, people love hearing low sounds. Whales, orangutan, various creatures of the night - they all love a low sound."
• On this track, guitarists David St. Hubbins and Nigel Tufnel play bass, and bassist Derek Smalls plays a double-neck bass, leaving just drums and keyboards to enhance the sound. When Tufnel briefly left the band, they had the keyboard player double up his bass pedal to perform it live.
• Conway Twitty had "Tight Fittin Jeans" and Dr. Hook had "Baby Makes Her Blue Jeans Talk," but "Big Bottom" was the first heavy metal booty song. The lyrics are filled with sexual euphemisms, including the famous couplet:
  
  My baby fits me like a flesh tuxedo
  I'd like to sink her with my pink torpedo
• "Big Bottom" was originally released on Spinal Tap's album Smell The Glove. After objections to the raunchy cover art, the album was released with a black cover. Spinal Tap believes Metallica stole this idea for their Black Album.
• Spinal Tap performed this song on the May 5, 1984 episode of Saturday Night Live with a guy who looked like John Belushi on bass synthesizer.
• The line, "My love gun's loaded and she's in my sights, big game is waiting there inside her tights," is a reference to the KISS song "Love Gun."
• Harry Shearer, who plays Derek Smalls, is a real bass player and often works on music with his wife, the singer-songwriter Judith Owen. Harry says the band has done a few different arrangements of this song, and they love playing it. Regarding his bass aspirations, he told Songfacts: "I practice every day and my real love right now is the upright bass. But I love playing both instruments. I live in a city full of great musicians, I know where I am in that pecking order. I'm fine with that. I don't have any illusions. I'm an amateur, but I work hard and I've been allowed to get on stage and jam with some acts down here. That's happened from time to time and I felt incredibly privileged and extremely nervous. But I love to play."
• Spinal Tap was the subject of the 1984 film This Is Spinal Tap, directed by Rob Reiner with Christopher Guest, Michael McKean and Harry Shearer playing the band members. These four guys wrote all the songs for the movie, which were used for the soundtrack album. In 1992, the band released another album called Break Like the Wind and toured to promote it.
• The band returned to action in 2025 with a new album and a big reunion concert in New Orleans. It was all documented in the film Spinal Tap II: The End Continues, where Paul McCartney expounds on the significance of the band and of this song in particular. "'Pink Torpedo,' that's literature, really," he said.