Conker's Bad Fur Day is a 2001 platform video game produced by Rare for the Nintendo 64. The game follows Conker, a greedy, hard-drinking red squirrel who must return home to his girlfriend, Berri after binge drinking. Most of the game requires the player to complete a linear sequence of challenges that involve jumping over obstacles, solving puzzles, and fighting enemies. A multiplayer mode in which up to four players can compete against each other in seven different game types is also included. It is the second installment in the Conker series, after Conker's Pocket Tales (1999).

Although visually similar to Rare's previous games, such as Banjo-Kazooie (1998), Donkey Kong 64 (1999), and Banjo-Tooie (2000), Conker's Bad Fur Day was designed for mature audiences and features graphic violence, alcohol and tobacco use, profanity, dark humor, toilet humor, fourth wall breaks and pop culture references. Development lasted four years, with concepts originating during the development of Killer Instinct Gold in 1996. The game, intended for a family audience, was initially titled Twelve Tales: Conker 64 and was set for release in late 1998, but by the time it received criticism for its kid-friendly tone and resemblance to Banjo-Kazooie during E3 1998, the game was transformed into an adult-oriented version of that product.