A/N: Based on SMG4's The Mario Channel: Mario's Challenge video. (PS: It is SO funny, I recommend watching it.) Also, it will be a Disney crossover with Disney and Pixar characters, such as Elsa, Anna, Olaf, Wreck-It-Ralph, Merida, Nick Wilde, Moana, Mickey Mouse, Tamatoa, Hans, Winnie the Pooh, 101 Dalmatians, Peter Pan, Taran, Tinker Bell, and etc. (No bad words though, with humor and rising stakes added to the story.) Split into ten chapters. I DON'T OWN ANYTHING.

PROLOGUE

On an exciting evening at the magical Disney Castle, a whole lot of Disney characters gathered for Elsa's newest event, as Elsa was watching the crowd from the top balcony of the Disney castle, with holographic screens shown by the castle to broadcast Elsa at the top.

Elsa announced, "Welcome, all, welcome! To the main event, Elsa's ultimate challenge! Thank you all so much for coming, Disney pals! Over 500 of you have been chosen to go through the Disney castle to try and reach the top!"

"HOORAY! Are there gonna be snacks, or refreshments?", Olaf glees.

Tamatoa craved, "Yeah! I just like free food...and they look like seafood..."

"Well, yes. Anyway, the prize is something even better...", Elsa continued.

Her sister Anna questioned, "Oh! What is it, sis? Is it a Disneyland vacation?"

"Better!", the ice queen said, presenting a surprise for everyone in the broadcast, showing a big gift box with her, "This mystery box!", as characters like Merida, Tamatoa and Wreck-It-Ralph were amazed, as Elsa said, "The first person to reach the top, gets the prize! But be careful, there's many obstacles along the way for the entire duration of the challenge."

Olaf and Anna were a bit nervous, while Wreck-It-Ralph, Merida, Nick Wilde and Moana look interested, and Hans, Tamatoa, Bellweather, The Horned King and Ratigan were grinning evilly to this.

"Oh, and by the way, no one's gonna die. The challenge will be injury-free, yet the stakes will still be high. Please play fair.", Elsa told the rules, as she began, "Let Elsa's ultimate challenge, BEGIN!", the entrance of the Walt Disney Castle opening.

All of the Disney characters but Elsa, such as Anna, Olaf, Nick Wilde, Wreck-It-Ralph, Moana, Merida, Hans, Winnie the Pooh, Taran, Tinker Bell, Arlo, Joy, Miguel, Woody, Buzz Lightyear, and others go into the castle, altogether preparing to face what's ahead of them...