Muppet Wars.

The Muppet Wars was a massive war that took place a decade before Sora became a keyblade warrior.

History
The Muppet Wars started when a horrendous man known as Jim Henson decided that the world was too pleasant and decided to rule it with an iron fist or otherwise destroy everything it held dear.

Unfortunately for the peaceful world, Jim Henson was skilled with ventriloquism. In fact, each Muppet he created came to life. He continued creating more and more Muppets with his dark powers, until finally he had an army of them.

He started by sending them to attack villages and towns, but unfortunately they weren't evil, they were just annoying. Jim Henson would not allow this, and he used his dark powers to make them progressively more and more evil.

Eventually, they would destroy the towns and villages like he asked, starting the Muppet War when people stood up to them.

The war eventually ended with the death of Jim Henson. Finally, the world was at peace...at least until Organization Sesame Street XIII arrived.

Sides
The Resistance

The Muppets

Commanders
Mickey Mouse

Jim Henson (KIA)

Casualties
Thousands of Muppets

Many members of the resistance

Gonzo

Fozzie Bear

Animal

Pepe

Professor Bunsen Honeydew

Winners
The Resistance