Foaly Matripony is the eighth episode of Friendship is Witchcraft. It uses video material from the episode A Canterlot Wedding - Part 1 and Part 2, as well as original animation created by Yohanes, Dinnerjoe, Belaboy, Silver Rainclouds, Olibacon, Artwork Cygaj, and OblivionFall, exclusive artwork by DrFrederickWilson, BlackMorass, SubjectNumber2394, along with music created by Forest Rain, Chelsea McAlarney, Lenich, Markarian, and Toastwaffle. Additional artwork was created by Dinnerjoe, Topshot, and GreenscreenPonies.
The Mane 6 are having a picnic while Spike is preoccupied with a panther they set on him. Spike hoewever, manages to lose the panther and get to Twilight just in time to burp out a letter for her from Princess Celestia, telling her that as part of her duties as "Princess of the Night" she is required to attend an upcoming wedding as well as assigning her friends a variety of tasks to keep them busy. A second letter then reveals that the wedding is between "Princess Cadence Not Evil Good Pony" and her brother "Francis Sparkle". Twilight is angry however, because her brother was originally intended to marry her, and she still has feelings for him. She claims this is not creepy since he isn't her biological brother. (Through the song 'It'll Be OK'.
The group then makes their way to Canterlot whereupon Twilight confronts her brother, waving off his excuses. She then gets to meet Princess Cadence, renown as whom Twilight immediately tells she is going to steal her husband. Later, while the Princess is checking on how Applejack is doing with the catering, Twilight watches her politely remind Applejack that she is allergic to apples. Applejack ignores this anyways and gives the Princess a bag full of apple confectionaries, to which the Princess throws the bag into a food donation bucket while Applejack is not looking. Twilight then goes to Rarity to complain about Cadence, when suddenly the mare in question walks into the room. Cadence tells Rarity that the dress doesn't really look like a wedding gown, despite everypony else saying it looks beautiful. Twilight then calls Cadence stupid after she leaves.
That night, Twilight tries to slander Cadence's name among her friends, before leaving angrily when she finds that it has little effect on her getting her own way. Twilight then makes her way to her brother, to confess her true feelings for him, but he is pulled aside by Cadence who tells him that she thinks Twilight and her friends are one-dimensional characters and that they are rubbing off on him. Twilight then casts a spell and Francis gets a sudden headache. Twilight starts shouting about Cadence being evil and runs away screaming. Twilight then regroups with her friends to tell them how Cadence is evil, but finds that they have been making puns for the episode's title without her. She then goes and lies on some stairs, claiming that they are her only friend.
Later, Princess Cadence is about to have her small personal wedding (having donated the wedding budget to charity). However, Twilight bursts in through the door and tells everyone that Cadence is evil, and that she hates her. After Twilight chases Cadence away in tears, the scene cuts to a far more extravagant wedding between her and her brother, which nobody finds weird because they aren’t biologically related. When Francis asks Twilight what she did with Cadence, she replies that she “took care of her”, which is to say she beat her up and ordered her to stay in the crystal caverns beneath Canterlot. Francis comments that he doesn't feel anything about that and Twilights tells him he won't ever feel anything again, hinting to the nature of Twilight's spell. A newspaper montage then plays, revealing that the wedding was widely accepted, Princess Cadence was never found, and that the panther is still loose in Ponyville. In the newspaper, there are still several references to other episodes, such as the pony from The Perfect Swarm getting sick from watering flowers and Newt Pipington British Hooves losing all of his outer body parts that are not required to survive.