Cast[]
- Thomas as Mario - (Both the main heroes)
- Casey Jr as Luigi - (Thomas and Casey Jr are great friends, just like Mario and Luigi)
- Peter Sam as Yoshi - (Both green and well mannered)
- Mellisa as Birdo - (Both pink)
- Emily as Princess Peach - (Thomas has a crush on Emily, just like Mario has a crush on Princess Peach)
- Tillie as Princess Daisy - (Casey Jr has a crush on Tillie, just like Luigi has a crush on Princess Daisy)
- Percy as Toad - (Both small)
- James as Wario - (Both vain)
- Spencer as Waluigi - (Spencer is a real villain in Hero of The Rails)
- Cerberus as Bowser Koopa - (Both strong, evil, and mean to Thomas, Mario, Casey Jr, and Luigi)
- Baby Thomas Jr. (if Baby Thomas was a real TTTE character) as Baby Mario
- Baby Casey Jr. (if Baby Casey Jr was a real CJ&F character) as Baby Luigi
- Baby Peter Sam (if Baby Peter Sam was a real TTTE character) as Baby Yoshi
- Baby Emily (if Baby Emily was a real TTTE character) as Baby Princess Peach
- Baby Tillie (if Baby Tillie was a real CJ&F character) as Baby Princess Daisy
- Troublesome Trucks as Goombas and Boos
- Tootle as Toadsworth (Both the have letter 'T')
- Devious Diesel as Bowser Jr.
- Gordon as Donkey Kong - (Both strong)
- Henry as Diddy Kong - (Both wise)
- Murdoch as Chunky Kong - (Both strong)
- Salty as Lakitu - (Both tell stories)
- Toby as FLUDD - (Both wise)
- Ivor as Funky Kong
- Donald, Douglas, Stanley, Rasmus, Toyland Express, Rustee Rails, Harry Hogwarts, Steam Lokey, Rasmus, Jason, Greendale Rocket, Tom Jerry, Doc, Jebidiah, Pete, Shelbert, Rusty, Humphrey, Rodrick, Dougal Train & Choo Choo as The Other Colour Toads
- Farnsworth as King Boo
- Pufle as Cranky Kong
- Tracy as Wrinkly Kong
- Mavis as Toadette
- Greendale Rocket as Donkey Kong Jr.
- Evil Thomas (if Evil Thomas was a real TTTE character) as Ludwig Von Koopa
- Evil Edward (if Evil Edward was a real TTTE character) as Lemmy Koopa
- Evil Henry (if Evil Henry was a real TTTE character) as Roy Koopa
- Evil Gordon (if Evil Gordon was a real TTTE character) as Iggy Koopa
- Daisy as Wendy O. Koopa
- Evil James as Morton Koopa Jr.
- Evil Toby as Larry Koopa
- Diesel 10 as Smithy
- Edward as Oogtar
- Johnny as Detective Herlock Solmes
- Emma as Candy Kong
- Madge as Dixie Kong
- Evil Duck as Baby Bowser
- Sir Topham Hatt and Lady Hatt as the Male Narrator and the Female Narrator
- and more