The Games Insiders

Project Dream was a game that got canceled by rareware this game was to be on the snes but then they started to make it on the 64 and it was a pirate themed RPG adventure game.But then Rare started to feel that the boy Edison did not quite fit the game anymore so they scraped the pirate theme and made a new  player who was a Bear they called him Banjo.
They  started to make the game a 2D platformer but rare then saw what nintendo was cooking up with super mario 64.
It was clear that 3D platformers where the future of gaming so they scraped the 2D dimensions and started again on a 3D platformer and a 3D platformer needs a double jump so to make real they gave Banjo a bird in his backpack who became Kazooie.
Then after building the first world  in Banjo Kazooie the team  finally new that they were on the right track.When they released Banjo Kazooie on the 64 it was a massive hit.One of the great 3D platformers of all time

There are plenty of secrets of Dream in the Banjo Kazooie games
For example you can find a photo of the 2D banjo game they were gonna make in Banjo's house
In Banjo Tooie you can find Captain black eye in Jolly rogers lagoon who was meant to be the main villain in Dream but sit's at table rating about a Bear stole his glory

So that is how Edison became Banjo and Kazooie