Based on commentary from Chris Seavor; the director of the game and the voice of all the male characters, Birdy the scarecrow was based on a programmer at Rare nicknamed "Beardy" (hence Conker initially thinking that he said his name was Beardy). He asks for Mepsipax because Beardy likes to drink Pepsi-Max, but they had to juxtapose the letters for copyright reasons.
Following the games release, Rare began working on a sequel titled "Conker's Other Bad Furday" but following Rare's buyout by Microsoft, Rare was told to remake Conker's Bad Fur Day for the XBox. By 2008 the sequel project was officially scrapped.
At the beginning of the "It's War!" Chapter, we see a newspaper with a squirrel soldier on it, called "The Midday Federal", headline "WAR". it also reads "In other news:" - "King Bee's Love Triangle" and "Ugas Die In Boulder Tragedy".
When Donkey Kong got his own video game on the SNES, Diddy Kong was the side-kick. Diddy got a videogame on the N64, called Diddy Kong Racing. In this, two other playable characters were Conker and Banjo. Banjo was the first of the two which got his own game, Banjo-Kazooie. In Conker's Bad Fur Day, in the Pub where the main screen is, Banjo's head hangs as a trophy above the fireplace, and Kazooie's head is in the "Chapter" room at the end of an umbrella.
When Rare began developing a Nintendo 64 title based around their Conker the Squirrel character in 1998, it was to be known as "Conker's Quest" (which was later changed to "Twelve Tales: Conker 64"), and would have followed a gameplay style similar to their massively successful platformer Banjo-Kazooie (1998). However, early previews of the game drew a lukewarm response from videogame critics, who felt it was too similar to "Banjo-Kazooie" to make any impact in the industry. Rare quietly went back to the drawing board and virtually began working on the game from scratch again, leading many observers to believe that "Conker 64" had been canned. However, in January 2000, Rare announced it's forthcoming releases for the year, which surprisingly included a revamped Conker title, now retitled "Conker's Bad Fur Day", a game which turned out to be completely antithetic of it's earlier builds.
When the big hayball loses a part of his face to show he's a terminator, he sees conker in terminator-style and scrolls a list of things he can say to conker. These are just three options repeated a couple of times. The three options are: "Buff you, asshole", "F*** you, scum" (this is not censored for the site, it is this way in the game) and "Blow it out your ass".
To this day there is no sequel to Conker, the latest game he has appeared in is Project Spark as a playable character. The creator of Conker's Bad Fur Day has said if he ever gets his rights back he will make a sequel but doubts that'll happen any time soon, and fans are making the assumption there will never be a sequel. There has since been a sequel released for the XBOX
When promoting this game, Rare partnered with PlayBoy and went around the United States to host multiplayer games at colleges. The winners were rewarded with Conker t-shirts and beer mugs. One of the winners was Neil Druckman, who would later go on to work for Naughty Dog.
The trivia item below may give away important plot points.
During the "It's War" chapter, there is a scene in which two Tediz are having a conversation out of character, and upon seeing Conker, immediately snap back into their mindless snarling. This scene was originally quite different in the Beta version of the game. The scene would start off much the same with Conker walking into the same room, but he would instead see two Tediz surgically eviscerating a still-conscious soldier, who is seen pleading for his life. This was likely removed due to Nintendo's objections to the disturbing tone and graphic nature.