Sometimes I think about how many weird doppelgangers/parallel rivals exist in the Mario Universe.
Mario has Wario and Foreman Spike.
Luigi has Waluigi
Yoshi has Boshi
Bowser has Midbus and Dark Bowser
Wario even has the Shake King, whose design parallels Wario's.
Jimmy T. has Jimmy P.
That's not even all of them.