"Monster" is a song by Canadian singers Shawn Mendes and Justin Bieber. It was released through Island Records as the second single from the former's fourth studio album, Wonder, on November 20, 2020. The song was produced by Frank Dukes and additionally produced by Matthew Tavares and Kaan Güneşberk. The two artists wrote it with Dukes alongside Daniel Caesar and Mustafa the Poet. All producers and songwriters are Canadian.

Rumours about a possible collaboration began in July 2020 after Bieber and Mendes were spotted with American singer-songwriter Tori Kelly, jamming around on a piano, when Bieber's manager, Scooter Braun, posted videos of them.^[1][2] In August 2020, the two artists were spotted with Bieber's wife, American model Hailey Bieber, at American record producer Andrew Watt's recording studio in Los Angeles, California,^[3][4] fuelling speculation of an upcoming collaboration between the two Canadian artists.^[5][6][7] During an interview on Capital Breakfast with Roman Kemp on October 6, 2020, Mendes was asked if he turned down a collaboration with Bieber in September, to which he replied: "Is this you trying to get me to confirm that I have a collaboration with Justin Bieber? I didn't last month". He said that it would be "insane" for him to turn it down, considering that Bieber has been one of his favourite artists since he was nine years old. He stated that he cannot confirm or deny", but added that their relationship in the past six months leading up to the time of the interview has grown closer.^[8][9] "It's really cool to have him as a mentor in a lot of ways, just to kind of talk through stuff with, because there's not many people who do this type of stuff," he furtherly explained,^{[10][11][12][13]} describing Bieber as "freakishly talented".^[14] The song marks the first time the two singers have worked together.^[15][16] In an exclusive interview for Apple Music, Mendes told Zane Lowe that the single is "about how society can put celebrities up on a pedestal and watch them fall". Mendes called it "one of the most special songs" he had ever written.^[17]

"Monster" is a pop song that is set in the key of D minor with a tempo of 146 beats per minute.^[18][19] Lyrically, the song is about the pitfalls and pressure of stardom. Mendes stated: "It's about how society can put celebrities up on a pedestal and watch them fall and it seems to be this entertainment thing. And it's hard."^[17]

The song was first revealed on September 29, 2020, when Mendes launched an interactive VR experience on a website for the album, in which a "set list" showed a track titled "Monster" with a special guest.^[20][21] On November 13, 2020, Mendes released the official album tracklist, confirming the song's title, while its co-lead artist remains unannounced.^[22] On November 16, 2020, Mendes and Bieber both posted a 13-second teaser clip on social media, officially announcing the release date of the collaboration,^[23] which serves as the second single from the album after "Wonder".^[24][25] The teaser features a synthy instrumental playing in the background, with the song's title, release date and the two artist's names overlaid on top of four outdoor scenes in dimly lit and foggy conditions,^[26][27] including an empty street with streetlights, a forest, and an empty platform with stairs.^[28][29] On November 18, 2020, Mendes and Bieber posted the song's cover art on social media,^[30] as well as pre-order links for the single,^[31][32] which includes limited CD singles with two different exclusive covers available on the singers' respective online stores.^[33][34]

The music video was directed by Colin Tilley and released via YouTube on November 20, 2020.^[36] The video is shot in one single take, and starts with Mendes walking through the woods onto a cube platform with stairs and continuing his performance there, before being joined by Bieber.^[37] Video director Rory Kramer released several images of the production on Instagram, including one showing a crane on location with a platform that enabled the camera operator to capture the video in a single take.^[38] The scenario captures the emotions in the song and what it is about.

The song debuted and peaked at number eight on the Billboard Hot 100, making it Mendes' sixth top 10 and Bieber’s 21st in the United States. Monster also debuted in the top ten in over fifteen countries, including the UK and Australia. Elsewhere, the song debuted at number one in Denmark and Canada, making it Mendes's second number one single and Bieber's 11th in the latter.

Bieber and Mendes performed the song for the first time at the American Music Awards of 2020 on November 22, 2020.^[39]

Credits adapted from Tidal.^[40]