After watching the initial Treehouse demo of Super Mario Odyssey, the developers revealed that the mayor of New Donk City happened to be Pauline, the once damsel in distress in the original Donkey Kong arcade game. In a reddit AMA, Yoshiaki Koizumi was asked where he got the idea for that quite frankly amazing E3 trailer song, "I'll Be Your 1 Up Girl". He said that canonically speaking, Pauline is the singer of that song since the developers knew she's be someone who would be into jazz. Personally I'd like to know who the actual singer is because she goes all out with this swinging jazz tune. Song is below:
Are there any other Mario characters, left field or not, that you all would want to see in this game? If Pauline is gonna be in the same game as Peach and Bowser, I wonder who else could make a surprise appearance. Part of me wants to see a reveal for the CEO of the Crazy Cap store chain and that person happens to be Wario. The colors of the store match his color palette and maybe there's a twist that Mario has been supporting a rival's business all this time, but honestly that probably won't happen.
Someone did find a cameo of one character in NDC and while this character may not be very left field, I don't know if many people thought he'd be in the game: