A crossover that doesn't just bring two worlds together, but several. But focuses on two. :P I hope you like this story.

It was a seemingly normal day in the Mushroom Kingdom, everyone was happy and smiling and Peach made another cake for Mario. Everything was just going well, for mostly everyone that is. Toad was a bit bored at the current moment, and he did not know why. He just wanted to go on an adventure of some sort, something more. He would sing about it, but he was not Peach or a good singer in fact so he picked up some things and put them in a smaller backpack and went out to find a warp pipe. He looked in the court yard with no luck of pipe going anywhere new, "Well Sarasaland is looking nice this time of year." He went up to the warp pipe and lined up so he can go down it, but then the ground shook a bit causing Toad to fall off the pipe. He got up and saw a new pipe, a dark blue one with stars on it, so, he went over to it and jumped in. What could go wrong?

Down in a jungle on Mobius there was one person who can fish like no one else. His name was Big and he was a cat with his best friend being a frog. They played games like hopscotch, go fish, and of course Leap frog. The two where tighter than blood, and not in the weird way some people might think. The two where just fishing in the jungle as you do when all the sudden Froggy started to hop away. Big as usual started to follow his green friend, "I wonder what's wrong with Froggy this time?" Big asked himself, as he watched his friend hop along. The two stopped by a weird out of place sewer pipe in the middle of station square, "That's odd, " Big commented, "There aren't supposed to be repairs on the sewers until next Monday." Froggy started to go too the weird pipe and jump in, so Big, being Big, followed his friend into the pipe to save him.

Toad popped out of the pipe he went down in front of a familiar face, a woman in a light blue dress and blench blonde hair. "Oh hey Rosey!" Toad cheerfully said, "What's with the sudden call?" Rosalina looked at the little guy "Hello Toad, it seems that the warp pipe worked for you." She floated over to the other warp pipe with two Luma with a giant plunger pulling out a big purple thing, "Sorry to make this sudden, but I need heroes." She stated as gave her mushroom friend some tea, "You see... The Multiverse is falling apart." Toad had a puzzled look on his face, just then the two Lumas managed to pull the purple cat out of the other warp pipe, with him landing on Toad. "Oh, I'm sorry Mr. Mushroom. Froggy took me to this place." Toad just grumbled a bit and managed to push him off, "What do you mean by failing?" Rosalina slowly pulled out a book, "Well you see. All beings of our type live in a Multiverse. Each part of the Omniverse has sections of Multiverses, some universes of a multiverse are closer together than others. It's imposible to destroy the Omniverse from our stances. However, you can effect all the sections by destroying one multiverse at a time. Something did that in a far off section of the Multiverse, it caused a dynamo effect. Though the heroes of that section thought they stopped it, they really made it worse. New universes need to be made to keep it balanced, and the ones that are still running need to stay like that. That's where you two come in." She then went over to Toad and took his backpack, "You two are going to be my knights," She stated as she started to wave her wand, "If you choose too that is." Toad looked confused, "Why us though? Why not Mario or Sonic, Tails or Luigi? Or even Shadow?" Rosalina smiled, "Because I figured you two had bigger hearts than any of them." Toad blushed a bit, "Well, when you put it like that." Big was still confused, and currently trying to figure out what was the difference between 'multi and uni. None of that mattered however when Rosalina asked him, "So Toad agreed to help, how about you?" "Sure Lady, I'll be happy to help! Anything to protect the world from harm, and protect Froggy." Rosalina was pleased, and with a wave of her wand she changed Toad's Backpack to a Cosmic Pack. "This has endless storage, I'll fill it with Power ups from both our universe and Big's. Collect other things from other universes as well, it may just help you on your quest to save all of them." She handed him the pack and took Big's fishing rod and transformed it to a strange combo, "This is the Hero's Blade. It's different for everyone, seems it turned into a fishing rod for you. Use this when you deem it fit." The two heroes looked at each other, then looked back at Rosalina. "When you two are ready go out to the docking bay. You'll meet an orange Luma who'll help you on your journey."

AS a bit of a note here, I was going to do this type of story with Mario and Luigi, but then figured to make it with two other guys. I wanted to make a Toad and Big story just for kicks and giggles, and then the two became one and now we got part one. :P