Banjo-Kazooie Nuts and Bolts Easter Egg - N64 in the Game.

This egg can only be seen during the intro movie, not when you gain control over B & K.

While the intro movie is playing, when Kazooie talks, pay attention to the side of the T.V. she is playing her game on. Beside it is a Nintendo 64.

However, when the movie is finished playing, it disappears.

This is probably to show a thanks to nintendo for letting their first game being released on their console.