A collection of islands situated somewhere in The Mushroom Kingdom Dimension, Dinosaur Land was named after its somewhat mysterious history. Legend has it that a group of dinosaur-like creatures, named the Yoshi, lived here in harmony. The Yoshi were named when a green one of the same name defeated Bowser when he was just a young boy in an attempt to save two babies. Although Yoshi have also been seen in Isle Delfino, as evidenced during Mario and the legendary Phil the Valiant's past adventure, they are not related to those on Dinosaur Land, and are thus considered relatives.

So, due to this legend, Dinosaur Land was the ideal vacation spot for the weary Mario Mario, his brother Luigi Mario, Princess Peach Toadstool and her loyal subject, Toad. They had been planning the vacation for weeks after they defeated King Bowser Koopa and his Koopalings with the help of the Embodiment of Peace, Nazzilla. The best way to get there, they decided, was via the use of a hot-air balloon that Professor E.Gadd created for them shortly before he became a chemist.

But unbeknowst to anyone in The Mushroom Kingdom, the peace made shortly after Bowser's defeat was to be broken again, this time through some outside help...

Ludwig Von Koopa turned off a nearby machine and surveyed the robotic remains. Ludwig was the smartest of the Koopalings and, as such, was the person behind most of the Koopa Troop's inventions. Since his sound defeat in World 8, Ludwig and King Bowser Koopa plotted that the easiest way to dispose of the Mario Bros. was to attack the outsider that had recently helped them: Nazzilla. Bowser Jr., the youngest of the Koopalings, found Dinosaur Land in an ancient book in Bowser's library, allowing them to devise their next hideout.

When they had got to Dinosaur Land, Ludwig detected massive signs of Portal activity, one of which led to the Real World. He also found out that Portals not only can lead someone to another dimension, but also to another time. He secretly watched the battle in Las Vegas between Nazzilla and RoboMandy--a robot built by General Skarr--and realized that RoboMandy would be of some use to them. Thus, he activated RoboMandy's mind circuitry via another Portal and watched as the titanic metallic girl limped through to Bowser's newly built castle, nicknamed the 'Coney Island Disco Palace' due to its flashing neon lights.

"This pile of junk needs retuning!" declared the Koopaling to his father. "It needs metallic parts found only in this part of Dinosaur Land!"

"Then I'll get the Bob-ombs ready to do some blasting." Bowser said. "How is my new vehicle coming along, son of mine?"

"It's almost ready!" Ludwig cackled. "Nazzilla may have destroyed the Airship, but she won't be ready to destroy...the Koopa Clown Car!"

The two Koopas laughed before they resumed their work.

Nazzilla was also working on something. It was October in the Real World, and Halloween was fast approaching. Before the annihilation of her world, Nazzilla celebrated Halloween with her friends and servant. Ever the one to enjoy a peaceful celebration, Nazzilla was working on her ultimate costume: 'Medusa Kong'. She was going to dress up as a giant-sized Medusa, complete with cardboard snakes around a band that she was going to wear in her hair. It was while she was finishing off her costume that she saw Adam Szalinsky's friends. They were distraught about something.

"Nazzilla, have you seen Adam lately?" said one. "We haven't seen him since August. The last time we saw him was during your battle with RoboMandy."

"LIKE, I HAVEN'T SEEN HIM, DUDES." replied the giantess. "MAYBE HE'S ON A VACATION SOMEWHERE. LIKE MY COSTUME?"

Putting on her giant, 600ft costume, Nazzilla hissed at the tiny teens. The teens shook with fear, then laughed!

"Wicked costume!" said one.

"You're bound to help us get candy with an awesome get-up like that!" replied another.

"GEE, THANKS!" Nazzilla said. Just then, she felt that pang in her stomach...

"LIKE, SOMEONE NEEDS ME," she replied. "I'LL BE BACK IN A LITTLE WHILE. SEE YA, LITTLE MEN!"

Nazzilla changed into her normal clothes with a click of her fingers, then disappeared into a light-coloured portal...

Meanwhile, Mario, Luigi and Toad were stood in disbelief at their balloon. They had told Peach specifically to stay in the balloon in case of trouble while they went exploring, but now Peach had gone, leaving the picnic basket untouched! It was then they saw the familar light-coloured portal, and Nazzilla soon came to view.

"HEY, GUYS!" said Nazzilla. "HAPPY HALLOWEEN!"

"What's Halloween?" asked Toad. "We don't have most of your strange Real World customs."

And Nazzilla explained to Toad about how people dressed up in costumes and celebrated the night the dead rose from their graves. Toad was amazed at the custom, then explained to Nazzilla about their current plight.

"SO, PEACH HAS GONE?" asked Nazzilla. "I'M SURE IT CAN'T BE BOWSER THIS TIME, DUDES!"

"I-a know!" said Mario. "Perhaps the dead-a got her?"

"Or maybe the natives kidnapped-a her for some sacrifice of some sort!" Luigi shook in terror.

"Well, we can't just stay here panicking!" Toad cried. "We need to find Peach!"

From his Neon Castle, King Bowser Koopa watched Nazzilla's entrance from a nearby Portal. He laughed, and then took out a book.

"Kids, did you hear what Nazzilla said?" asked Bowser.

"Something about..." Iggy began.

"...Halloween!" Lemmy finished. Both Iggy and Lemmy Koopa were twins, and were able to finish each other's sentences.

"Yes, but this book on 'Ancient Dinosaur Land Mythology' states that an equinox between the Real World and the Mushroom Kingdom occurs on the night of Halloween. A Portal will open up when a Full Moon appears in the bright night sky, leading to the Real World. That means we can take over both Dinosaur Land AND the Real World. And all the better with RoboMandy2 to help us!"

He turned to Iggy and Lemmy. "Go to one of the Ghost Houses in Dinosaur Land and find some Boos to assist us in our plan! If they could trap the Yoshi that live here in the ? Boxes, they could possess RoboMandy2 and help us defeat Nazzilla!"

Since landing in Dinosaur Land, Mario and Luigi had the strange feeling that they were there before. As they walked across a part of the island called The Forest of Illusion along with Nazzilla and Toad, Mario tripped over something in the fauna. He picked it up. There was a crayon drawing of a group of Yoshi along with two babies that looked very familar...

"They look like you two!" Toad observed. "Look--they have the same hats as you do!"

Just then, Luigi saw something else!

"It's-a Nazzilla!" he cried. "What is she-a doing on the mural?"

Unbeknowst to all of them, Nazzilla would meet their baby forms sometime in the future, when she would learn about travelling to and from the future via her portals.

Before anyone could answer, they stumbled upon a Ghost House. Ghost Houses were once full of natives that lived in Dinosaur Land, even before the Yoshi were discovered. They died, leaving their souls, which took on the form of Boos: spherical ghosts with pointy teeth and stubby hands. And the Boos were there on the day Mario found them!

"Looks like they don't want us around!" cried Toad, as he heard their cackling laughter behind him.

Mario turned around, but the Boos covered up their faces in terror. Boos are anti-social, and also hate the light. When someone comes up to them, they cover their faces until they turn around, where they then pounce!

They floated towards Nazzilla in interest. But when she turned around, they ran away in fright!

"COOL!" she giggled. "THEY WERE AFRAID OF ME! AWESOME!"

Just then, Mario saw some familiar shadows from within the Ghost House.

"It's-a the Koopalings!" he gasped. "So they DID-a survive my battle!"

The door creaked open to reveal Iggy and Lemmy, with a line of Boos floating behind them. They opened a Portal, and walked into it!

"Where did they go?" asked Mario.

"LIKE, TO BOWSER'S CASTLE, POSSIBLY." Nazzilla replied. She then saw a ? Block. Poking it with her finger, she revealed a Feather and a Yoshi Egg. Mario grabbed the Feather and instantly sported a yellow cape! Mario soon learnt that he became Cape Mario: like Raccoon Mario, but with more agility and power. The green-spotted Egg landed on Luigi, and hatched into a green dinosaur!

"Yoshi!" shouted the dinosaur intently. Mario looked at the mural he collected earlier, then put two-and-two together.

"Now, I-a get it! You-a helped me when we were babies along with-a Nazzilla! But who did-a this to you?"

Yoshi pointed at the picture of a younger form of Bowser.

"BOWSER!" everyone cried.

"Let's-a go and save the Yoshi from-a Bowser!" Luigi cried gallantly. And, via Nazzilla, they walked to Bowser's Neon Castle.

Bowser was outside, along with RoboMandy2. He watched the Boos circling round, gurgling with curiosity at the new body. They floated in, and activated the mecha from within! A green aura flashed in the windows of the RoboMandy2 cockpit, just as a purple flash appeared in the sky, along with a clash of thunder and lightning.

"STOP RIGHT THERE, BOWSER!" called Nazzilla.

"You're too late, Nazzilla!" cackled Bowser. "I'm sure you've met RoboMandy before. Well, now you're gonna battle the upgraded version! The equinox to the Real World has opened, and I'll take over it for The Chaos Lord!"

"You won't be doing anything, Bowser!" cried Toad. "Unless you free the Princess and the Yoshi!"

"Oh, you can have the Yoshi Eggs back," Bowser laughed. "Now that the Boos are piloting the RoboMandy2 with more efficency than a pile of eggs, your giant friend won't be able to stop me!"

And with that, he flew into the Portal in his Koopa Clown Car, a helicopter-like machine with a picture of a menacing clown's face. In the cockpit, the Princess was screaming in sheer terror. RoboMandy2 then walked into the Portal as well!

"We'll-a leave you to sort your friends out, little buddy!" Luigi said to Yoshi. "Unless you wanna come back to The Mushroom Kingdom with-a us."

Yoshi shook his head. He preferred to live on Dinosaur Land. As he waved goodbye to his new friends, he was sure that he would meet them again some day...

Back in Las Vegas, everyone ran in terror as RoboMandy2 was in full force. Firing off lasers from its fingertips, the mecha was surrounded with Bowser's Koopa Troop, who were already in action. Nazzilla, Mario, Luigi and Toad stepped into the action.

"I'll-a take care of the Koopa Troop," Luigi said. "Mario, you'd-a better take care of-a Bowser."

Mario took a run up, and then flew upwards to a nearby skyscraper, his Cape billowing in the wind. Toad ran with Luigi, stepping on Goombas and throwing Red and Green Shells at Koopa Troopas, leaving the path clear for Nazzilla to battle with RoboMandy2.

Nazzilla punched RoboMandy2 straight through the middle. RoboMandy2 fired lasers from its fingertips and also fired missiles full of fireworks (obviously the work of Ludiwg Von Koopa). The ammunition fired off Nazzilla's body, allowing the giantess to headbutt the mecha in half.

The Boos were shaken free, and flew back into the Portal to Dinosaur Land. Meanwhile, Mario looked up at Bowser in his Koopa Clown Car. Bowser flew about, throwing down giant spherical balls. Mario dodged them, then flew about the Koopa King. But Bowser had another trick up his dirty sleeves. He threw down Mecha-Koopas: mechanical Koopa Troopas made from the leftovers of RoboMandy that couldn't be renewed. Mario picked them up and threw them into the Koopa Clown Car. With a great heave, the Koopa Clown Car exploded, with Mario catching Peach heroically as Bowser was flung into the Portal. Nazzilla took the opportunity to fling the scrapped pieces of RoboMandy2 into Dinosaur Land as well.

A while later, Nazzilla and the gang had just finished their Trick-or-Treating. Toad was estatic; he never knew how much fun Halloween could be. But, just as she could say goodbye to her friends, as they flew into Dinosaur Land via Mario's Cape, a green, emerald-like light trapped Nazzilla. Her image became distorted as she disappeared from view entirely!

On an island somewhere in another dimension, a red bipedal echidna watched all that was going on from a giant emerald in a secret altar. Turning to a person in the darkness, he uttered:

"Shego, it's Nazzilla! I, Knuckles the Echidna, have found her!"