The Day of Fire changed everything; it was the day when the moon died and the sun cried, it was the day when pumpkin was fried and Ahuiztol was denied... and it was also the day that Checkers, the black and red dragon, was hatched.

So, I'm going through Sanderson's lectures on writing, and he mentions a bet Jim Butcher took to make a book out of two "lame ideas" (Pokemon and the Lost Roman Legion); the result being Codex Alera -- For my coursework under his lectures I've done the same, taking several "bad"/"lame" ideas and running with them.

Bad Ideas That Will Be Appearing:
A red and black dragon OC.
Conversion Bureau.
Rainbow Dash becomes a penguin.
Rainbow Dash/George Washington.
A quarter of Equestria's population spontaneously combusts.
Overall Method: Gardening
Target: 50,000 Words.
(Thanks again to everyone that suggested them.)