Twilight Sparkle Alicorn Controversy refers to a plot twist in the animated television show My Little Pony: Friendship is Magic in which the character Twilight Sparkle is transformed into an amalgamation of a pegasus and a unicorn known as an "alicorn." The character change sparked many discussions among those in the brony fandom after rumors began to spread online in September of 2012.
On September 30th, 2012, the plushie manufacturer Funrise posted a picture on their Facebook page with several My Little Pony plushies in an office, with one Twilight Sparkle plush toy wearing wings (shown below, left). On October 17th, the licensing convention Brand Licencing Europe shared a picture on their Twitter with a poster featuring Twilight Sparkle with a pair of wings (shown below, right). The same day, Redditor Lusht submitted the photo to the /r/mylittlepony subreddit, where it received over 490 up votes and 200 comments within the next three months.
The news was met with a variety of responses from the brony fandom. Many felt that changing Twilight Sparkle into an alicorn could severely damage the character by over-idealizing her, similar to the Mary Sue phenomenon in fanfiction. On November 1st, 2012, a poll was posted on the MLP Forums, to which over 43% said they did not approve of Twilight Sparkle becoming an alicorn (shown below).
On January 29th, 2013, the entertainment news site Entertainment Weekly published an interview with My Little Pony: Friendship is Magic head writer Meghan McCarthy, who announced Twilight Sparkle's transformation into an alicorn, noting the character "was set up from the very beginning to be on an important journey." The same day, the announcement was reblogged on several brony news sites, including Equestria Daily and Derpy Hooves News.
Shortly after the announcement, the header of 4chan's /mlp/ (ponies) board was changed to "WHERE IS YOUR GOD NOW" (shown below, left) while playing the Metal Gear Solid 4 Love Theme in the background. An Equestria Daily poll was posted on January 20th, 2013, which indicated that a majority of voters were ambivalent toward to the transformation (shown below, right).
On January 27th, DeviantART user PixelKitties created a badge reading "I Believe In M.A. Larson", being related to M.A. Larson being the writer for the episode in which transformation occurs. Following this, numerous fans changed their avatars to include the button to show their support for the show.
On January 30th, Tumblr user bronychilensis-gwain published an animated GIF pointing out that 4chan's /mlp/ board was relatively calm regarding the Twilight Sparkle news in comparison to the websites DeviantArt, Equestria Daily, Ponychan and Reddit. Within five days, the post received 1,900 notes.
On February 1st, a thread was created on The Round Stable Forum, featuring various "Thanks, Obama!" GIFs edited to include My Little Pony: Friendship is Magic writer M.A. Larson's name (shown below). In less than 3 days, the thread garnered more than 80 responses.
Within the show's canon, alicorns commonly fulfill roles of deities and royalty, maintaining abilities that often far exceed regular ponies such as controlling the sun and moon. Although Twilight Sparkle already has an exceptional skill in magic compared to the average pony on the show, she still maintains no function as either a deity or royalty.
When Twilight Sparkle does become an alicorn, various fans fear that her new position and abilities will seperate her too much from the regular cast and that she will become over-idealized, in a similar vein to the Mary Sue phenomenon. By extension it also makes them fear for the series' direction, with this event representing the peak of character and plot development.
Episode writer Mitch Larson and Twilight Sparkle's voice actor Tara Strong responded to the online reaction by publishing tweets directed to fans joking about the controversy (shown below).
The developer of the series, Lauren Faust, has implied in tweets that the current course of Twilight Sparkle doesn't match her original intentions for the character but noted that she has no intention of undermining the show's current writers.
On February 16th, the season 3 final episode, "Magical Mystery Cure," aired, which featured Twilight Sparkle turning into an alicorn.
 Entertainment Weekly – 'My Little Pony: Friendship Is Magic' exclusive: Twilight's becoming a princess!
 Equestria Daily – Brand Licensing in Europe's Twilight Sparkle Derp?
 Equestria Daily – Poll Results: What Do You Think of the Twilacorn Rumors?