Mario/Adventures of Sonic the Hedgehog

Cast

 * Mario as Sonic (Mario and Sonic are both main stars)
 * Yoshi as Tails  (Yoshi and Tails are both young and are both best friends to Mario and Sonic)
 * Bowser as Dr. Robotnik (Bowser and Dr. Robotnik are both main villains)
 * Blue Koopa Kid as Scratch (Blue Koopa Kid and Scratch are both blue)
 * Green Koopa Kid as Grounder (Green Koopa Kid and Grounder are both green)
 * Red Koopa Kid as Coconuts (Red Koopa Kid and Coconuts are both red)
 * Koopa Kid as Robotnik Jr. (Koopa Kid and Robotnik Jr. are both sons to Bowser and Dr. Robotnik)
 * Clawdia as Mama Robotnik
 * Giga Bowser as Super Robotnik
 * Rosalina as Breezie
 * Peach as Ms. Possum (Peach and Miss Possum are both crush Mario and Sonic)
 * Luigi as Lucas (Luigi and Lucas both have names starting with "Lu")
 * Birdoas Lucinda (Daisy and Lucinda are both girlfriends to Luigi and Lucas)
 * Toad as Rocket
 * Popple as Dr. Quark
 * Rookie as Doofus
 * Smithy as Music Destroyer
 * Pauline as Catty Carlisle
 * Ice Bros. as Ball Hog
 * Sumo Bros. as Bat Brain
 * Mallow as Big Mike
 * Geno as Big Grizz
 * Cosmic Mario as Pseudo Sonic
 * Dry Bowser as Dr. Warpink
 * Professor E. Gadd as Professor Von Schlemmer
 * Birdo s Sonnet
 * Kalyepso as Omeletta
 * Queen Bee as Katella
 * Baby Mario as Baby Sonic
 * Baby Yoshi as Baby Tails
 * Baby Bowser as Baby Robotnik
 * Bullet Bills as Wired Earp
 * Wigglers as Batch Cassidy
 * Chain Chomp as Billy the Kit
 * Hammer Bros. as Chassis James
 * King Bob-Omb as DOS Holiday

Version 2

 * Mario as Sonic (both main stars)
 * Luigi as Tails (both best friend to Mario and Sonic)
 * Bowser as Dr. Robotnik (both main villains)
 * Blue Koopa Kid as Scratch (both blue)
 * Green Koopa Kid as Grounder (both green)
 * Red Koopa Kid as Coconuts (both red)
 * Koopa Kid as Robotnik Jr.
 * Bowletta as Mama Robotnik
 * Giga Bowser as Super Robotnik
 * Dry Bowser as Dr. Warpink
 * Wario as Ball Hog
 * Waluigi as Bat Brain
 * Peach as Miss Possum
 * Daisy as Breezie
 * Yoshi as Lucas
 * Birdo as Lucinda
 * Toad as Rocket
 * Mallow as Big Mike
 * Geno as Big Grizz
 * Smithy as Music Destoryer
 * Popple as Dr. Quark
 * Rookie as Doofus