Infamously, the ending cutscene of Banjo-Tooie has series antagonist Gruntilda threaten "Just you wait until Banjo-Threeie!". Contrary to popular belief, the lead designer for the Banjo-Kazooie series, Gregg Mayles, has stated that a direct sequel to Banjo-Tooie was never planned for development, and that the supposed "tease" was merely a joke, playing on how the word "Threeie" would be unpronounceable in British English. Instead, Banjo-Kazooie: Nuts and Bolts was actually the third attempt at creating a different kind of Banjo-Kazooie game to act as the third mainline installment in the series. The game initially began development as "Banjo X", a morphed "remake" of the first game for the original Xbox which featured some new assets and items. When development shifted to the Xbox 360, Mayles stated the game shifted to being about "an AI-controlled Grunty, who would be competing against Banjo in all the worlds". Around this time, development began on a kart racing title called Banjo-Kazoomie, which programmer Brendan Gunn reported working on for about two weeks. All of these builds were planned to incorporate multiplayer gameplay, but none of them made it far into development before being consolidated into what would become Banjo-Kazooie: Nuts and Bolts.