Celestia and Luna were unicorns originally, but Discord gave them wings and forced them to fly around as a practical joke. They later overthrew him using the Elements of Harmony and decided to keep the wings. 'Tis my favorite headcanon.
Luna didn't choose to become evil, she was possessed by something. (Slightly confirmed in the "Nightmare Rarity" MLP:FiM Official Comics arc. That's only assuming that you accept the comics as canon. Which I do. Until I'm shown or proven otherwise.) Other than that, I can't really think of anything else. If I do, I'll be sure to post it here though.
Personal headcanon: IDW comics are not canon to the show. That said, most of them are still enjoyable, like a good fanfic. Another personal headcanon: The Tumblr blogs Ask Flufflepuff and Ask King Sombra tell the story of what really happened to Chrysalis and Sombra.
My headcanon: What IS canon: -The TV show (most episodes) -The IDW Comics -The novels -The first EqG film -The upcoming 2017 film What is NOT canon: -Rainbow Rocks -Putting Your Hoof Down -Any fan-made episode (Double Rainboom, Dusk's Dawn, we're looking at you.) Also, Rainbow Dash is bisexual, Twilight is autistic, and Fluttershy has both PMS and PTSD. Sent from my SCH-S720C using Tapatalk 2
Because Rainbow Rocks has no reason to exist, and as for Putting Your Hoof Down, well, here's a quote from the episode... "Things getting too complicated for your simple little brain, Pinkie Pie?" Who said this, you may ask? Fluttershy. FLUTTERSHY! And I don't even like her. She also insults Pinkie and Rarity's reasons to live. Their REASONS to LIVE. Sent from my SCH-S720C using Tapatalk 2
Ah,but does the show have a reason to exist?I mean does it really have a reason to exist other then promoting toys? By this logic the show itself isn't canon.And what reason does the first one have? Now for putting your hoof down. Just because you dislike a episode doesn't mean it's not canon.
Iron Will appears in the IDW comics, and the episode is referenced. Therefore, if you accept the IDW comics as canon, you must accept Putting Your Hoof Down as canon.
Yes, it does, as a matter of fact. It exists to bring My Little Pony to a new generation of little girls, while making it tolerable for everyone else. It adds to the story of the show. Rainbow Rocks does not. Or you can pretend that Iron Will is a comic-exclusive character.
So you are just going to ignore an episode because you dislike it, what a brilliant plan. And how does the first movie add anything to the show?
So you think that the novel "rainbow rocks" (witch is a prequel to the movie) is canon but the movie isn't? Also why do you think that the upcoming movie is canon when you don't think that "rainbow rocks" is?
Actually, the only thing from the first movie that had any effect on S4 were a few cameos by Flash Sentry. Whether or not anything from the second movie will play a part in the show remains to be seen.