Development on "Twelve Tales: Conker 64" began around the same time as "Project Dream" (later "Banjo-Kazooie"), however work on the game was put on hold for a long time to focus on improving "Banjo-Kazooie" and other experiments.

There was a sequel being developed called "Conker’s Other Bad Day", however it was canceled.

The plot would've dealt with Conker's bad tenure as King after spending the treasury money on beer, parties and hookers. The game started with his escape, with a ball and chain attached to him, from the Castle's highest tower where he had been faced with the prospect of execution.

The opening sequence of Conker's Bad Fur Day is a parody of the intro from the Stanley Kubrick film "A Clockwork Orange".

If you input curse words or insults into the cheat menu, the fire devil will hurl insults back at you.

Originally there was a cutscene making fun of Pikachu in the game. After hackers discovered a Pikachu tail in the game's code, a fan asked the game's designer about it and he told the story in a tweet.

On the charcter select screen (the bar), you can see Banjo's severed and stuffed head mounted above the fireplace and if you look in the closet you'll find Kazooie's stuffed head being used as an umbrella handle.

Conker's Bad Fur Day started out as a sequel to Conker's Pocket Tales called Twelve Tales: Conker 64, but was changed to the more mature Conker's Bad Fur Day due to people calling the game 'cutesy', making Rare overreact.

Around the time of its announcement, Rare had already made two similar games, Banjo-Kazooie and Diddy Kong Racing. They feared criticism for making another innocent platformer starring cute animals. So, in 1999, Rare Ltd. revealed that they were going to redesign the game to appeal to an older audience.

If you stand idle for a while, Conker will get out his Game Boy and play it. You don't get to play with it, but you can hear him playing Killer Instinct, another game made by Rare.

Chris Seavor voiced all of the male characters in the game besides The Great Mighty Poo.