The Fairy Apocolypse

This is today, the day we (Shadow and Gingeh) started this timeline.

The fairies burst forth from the Earth and reign DOOM down upon our DOOMED Earth of DOOM.
Notes: the term "fairy" is a VERY general term. It can apply to fairy creatures, like, well, fairies and unicorns, but it also applies to wizards and zombies and stuff like that. Basically, anything magicalful. There were also many dramatic revealings of fairies that had secretly crept through the Earth and joined us long ago, such as the demon-summoning magicians, who have dispersed themselves all across the country and dominate the government.

At first, literally EVERY HUMAN who had been born on the surface was flipping out over the fairies arrival. News reports, day-to-day gossip, etc -- it was all dominated by the catastrophic revelation that -- surprise, surprise! -- humans were NOT the only intelligent life forms who lived on the Earth.
However, this craziness calmed down soon afterword as the humans adjusted to their new neighbors, and for a while, all was well ...

The reason the fairies burst from the Earth was because they needed to escape the Plague that was spreading beneath the surface. They didn't tell the humans this, mostly because if they did, the humans would probably have kicked them out to make sure the Plague didn't spread to THEM.
Well, only those who were screened not to have the Plague were let out onto the surface anyway, so nobody thought anything bad would happen. But it turned out ONE infected talking bunny had escaped the radar of the border patrol, so thus DOOOOOM was unleashed out upon the world. March 25 was the day that the first human on Earth, a Mexican guy named George (don't ask), saw the cute little bunny, went "AWWWW COSA ES LINDO!" (translation: "AWWWW THAT THING IS CUTE!"), and pet it. Of course, this meant that he had now caught the Plague and doomed most of humanity, but hey -- that thing WAS pretty cute.

For the next seven years, the Plague spread from human to human. Luckily, the Governments of the Americas saw it fit to completely quarantine both North and South America so that all of humanity wouldn't be wiped out. Slowly, without foreign imports and everybody going crazy from the Plague, the humans in the Americas devolved from a sophisticated (albeit stupid) society to a primitive one. The Americas have since been known as "the Land of Desolation" or "the Land of the Plague" and it is now forbidden by every government in the world to go there.

After years and years of hiding, the people of Oz revealed themselves to the outside world. They had been watching and laughing at human stupidity and eventually decided that they might be of use to the idiotic humans who were making a mess of their new world.
A note: Oz has always been Oz, but the Ozites fooled us into thinking that they were Australia for centuries. They're really quite clever.