Outside-of-universe-but-still-show-related examples such as commercials, toys and other merchandise, outside references and Real Life. Fan Work, however, has its own page and should be placed there instead.
The Jingle Bells ad. It starts with singing from numerous characters from various shows, including Applejack, Pinkie Pie and Rainbow Dash... then the B:tASJokerhijacks the song with the famous Batman parody version, much to Pinkie Pie's audible annoyance. Old-school Robin's reaction to the "Robin laid an egg" verse is also glorious.
The Hub's marathon prior to the season 2 finale for Transformers Prime has Megatron acting as the host. In one bumper, he asks Soundwave to play his favorite song. MLP's theme song plays: "Ahh, good stuff!" *Soundwave nods*
At least one description for Call of The Cutie called Apple Bloom "Apple Blossom".
This is an alternate version of this behind-the-scenes video, with the audio (presumably unintentionally) slowed down. Due to the audio and video becoming more and more desynchronized, Applejack ends up saying "We're hidin' from her!" right when Princess Celestia is shown.
One of the animators did a behind the scenes type video series called "Evolution of a Scene", and always ended them on a funny bit of animation like Gilda appearing in the middle of Fluttershy's "Cutie Mark Chronicles" flashback or Derpy appearing alongside a bunch of derp-eyed pets, but the best one was #6, which ended with the Wonderbolts vs MAGNEIGHTO!
ScrewAttack had Rainbow Dash vs G1 Starscream for one of their Death Battles. When it's not being awesome, it's being hilarious. Besides, G1 Starscream getting his ass kicked is always funny.
Boomstick's sheer incredulity at what they're doing just keeps getting funnier.
Wiz: (on the Wonderbolts) They're sort of like the Blue Angels. Boomstick: Except they're ponies!
The ending was hilarious, and COMPLETELY in character for Rainbow Dash. Starscream's Spark appears above his wreckage and starts taunting her, so she eats it!
Discord's trading card has the text turned upside-down. Yes.
Speaking of Discord, a poster came out featuring all the villains (or jerks) of the show. In the middle is Discord pulling Nightmare Moon and Chrysalis into a hug. Really.
And one more. The official Season 2 poster has him critiquing his own statue. There are some things you just can't write.
BigBadToyStore.com startedusing a logo advertising My Little Pony Friendship is Magic Shorts, suggesting that there would be Short Films in addition to the TV show. Said logo was soon discovered to be merely fanart, but at around the same time, WeLoveFine.com came out with a different type of My Little Pony Friendship is Magicshorts.
At BUCK 2012, the musician panel on day two with General Mumble, EqM, Lavender Harmony, and Pipsqueak has some great moments, particularly from Pipsqueak. Throughout the panel, he has plenty of funny one-liners and Self-Deprecation (the first words out of his mouth aside from an introduction are actually expressing glee that he gets to answer a question), but his greatest moment may have been when one person asked the musicians if there were any other brony musicians they'd like to collaborate with.
Pipsqueak: I really wanna collab with Mic the Microphone, but he's busy, like (...) constantly, and he's just doing his things...like...reading fan fictions and stuff...and so I never get to make music with him.
Lavender Harmony: I've collabed with Mic the Microphone.
As the other voice actors started to channel the voices of characters they have previously voiced, Quinton spends the entire reading doing celebrity voice impersonations including Christopher Walken, Ringo Starr and Sean Connery, all with hilarious results.
There were several more moments from that con as well. At the Brony Musician Panel, everyone on the panel decided to introduce themselves as Alex S. note a very popular brony musician who wasn't even at the panel.
Not to mention the several smaller moments throughout the con, including but not limited to a random singing flashmob forming before the Grand Galloping Gala, a guy dressed as a ninja constantly walking around, and the voice acting panel deciding to troll Tara Strong by having everyone in the room stay completely silent when she entered. Really, the entire con was hilarious, when it wasn't being awesome.
No mention of how Tara epically counter-trolled by entering in full Twilight Sparkle cosplay, which caused everybody to bust out laughing and totally ruined their silent gag?
A preview of Gameloft's game shows Big McIntosh dancing while surrounded by Bon Bon, Zecora, Cheerilee, and Mrs. Cup Cake.
The marvelous way the preview clip of "The Failure Song" trolled the audience. Twilight manages to go through the whole song without mentioning what she's actually singing about, then Spike asks what they were singing about...end clip.
Even better is that in the full episode, we already know exactly what she's singing about when the song comes in, meaning it was structured that way entirely so it could be used like this.
During the Season 3 premiere, commercials for Gak played so often (once even four times in a row, two of which were the very same commercial) that many fans latched onto it. The result was Gak getting its own post and a myriad of fan art and fan vids being created to make it a Memetic Mutation within a matter of hours.
4. A new season of Friendship is Magic premieres on The Hub.
At the same panel, Meghan also explained that writing an episode begins with them brainstorming simple premises and listing them on a whiteboard. She then mentioned that, when they're done, she likes to troll whoever comes into the meeting room next by writing "Applejack Pregnancy Scare" on the board.
Despite the whole Alicorn Twilight thing being a massive Base Breaker for the fandom, it obviously isn't for the staff. M.A. Larson, who wrote Magical Mystery Cure later wrote on Twitter "I went to the store to get some dog food and the guy turned into an alicorn Why does this keep happening?!!" If the writers can joke about it, then they must obviously know it's not a big deal.
The best part is that he appears to be fully aware of the stir that alicorn Twilight would cause. Before the thing was even officially announced, he was already having fun with it. He had at least one twitter post that went something like "The thing I'm most infamous for hasn't even aired yet!"
The April Fools fake series 4 episode titles. Particularly the last two: "Princess Discord" parts 1 and 2. Again, the writers seem to love poking fun at the Broken Base over Princess Twilight.
Speaking of fun poking, one of the aforementioned names involves Sunset Shimmer, who Word of God said would not be appearing on the show; trolling at its' finest.
It got even better when it turned out at least five of the titles (though not the accompanying synopses) were real.
Lauren Faust herself having a "Dear God make it stop" moment when she starts posting ways to avert Nobody Poops on her Twitter page.
Hot Topic did a series of their "Hot minutes" (minute long interviews with celebrities) with Fluttershy, Rainbow Dash, Twilight Sparkle, Pinkie Pie, & Rarity, and they all have their own moments of hilarity (the Twilight one even asks her about the Cadance toss meme "I think I'd still rather he didn't"). note the Twilight one is particularly notable, as it features a clip of Twilight attempting to fly and falling while her friends watch on, which is set in the Crystal Empire, which turned out to be from the intro to Equestria Girls. Ditto the Rarity one, which shows what can only be the opening to season 4, updated to include Twilight with her new alicorn wings..
The revelation that Pinkie Pie has three party cannons.
The six-hundred and sixty-sixth EQD Nightly roundup. Seth pretends it's a normal post, but starts tossing in some Zalgo text, and then further examination quickly descends into an outright horror-post with creepy music, scary images and satanic videos. Funny for how straight-faced Seth posts, as well.
Meghan McCarthy called Amy Keating Rogers during her panel at Everfree NW to make sure she isn�t telling that �Pinkie Pie�s becoming an alicorn.�
From the season 4 animatics at Comic Con, the Apple Family has a song welcoming Pinkie along on a family trip...ending with their cart falling apart.
There's a new Running Gag at BronyCon 2013: every time someone says the word "fun" (or any reasonable synonym thereof), the audience starts chanting "fun" ala Too Many Pinkie Pies.
Also at BronyCon 2013 was the Whose Line is it Anypony? panel, which was naturally full of all sorts of moments. A few examples:
In Hollywood Director, Pony Vegeta (playing Scootaloo) gets down on his knees to be a filly. When the director (RLYoshi) confronts him about this, he says "I'm Scootaloo! I'm short! I'm a filly!" He then wonders if he's not short enough and crouches down further.
"I have to remember that famous Shakespeare quote. It went something along the lines of...booty booty booty booty rockin everywhere!"
"ALAS POOR BOOTY!"
"That's even worse than...buddy cop movies!"
After the first three games, the teams are switched up; the four people onstage leave and three more people come on. Then the host SuperSonik says that RLYoshi was supposed to still be up there...cue RLYoshi rushing and half-stumbling onstage.
SuperSonik decided to ask the audience for suggestions for superhero names. Cue the entire crowd yelling at him incoherently.
Tweak's superhero name? "The Alicorn Wing Giver". Hilarity Ensues is all that can be said, especially when he gives RLYoshi a baker's dozen of wings at the end.
Quick Change gives us plenty of fun, from Alex (Princess Cadance) giving Penny (Queen Chrysalis) fashion advice to "Elements of Harmony Punk Rock Band". The entire thing is hilarious, and it needs to be seen to be believed.
Props. Tweak decides to shake things up and, instead of taking two of the same prop for his team (himself and RLYoshi) while leaving two of a different prop for the other team (Alex and Penny), he takes one of each prop. The other team has to do the same. And they roll with it.
Two of the props are plungers. SuperSonik says that the members have never seen these props before.
At the end of the "Easter Sunday Sing-A-Long" commercial, Russel attempts to sing My Little Pony main theme. Pinkie's jaw drops (which Rarity fixes for her) at how horribly off key he is.
At BABSCon in April 2014, the two VA panels went slightly off the rails in their own ways:
First panel (Saturday): Peter New doesn't come out on stage when the moderator announces him. When everyone else has taken their seats, he finally appears - dressed in a red gown with wings as "Princess Big Mac."
Second panel (Sunday): Writer Josh Haber and director Jim Miller sneak into the line of people waiting to ask questions and pass themselves off as geeky-sounding fanboys. They end up sitting among the VA's for the rest of the panel, as does supervising director Jayson Thiessen.
Almost all the Mane Six declare they'll go to the spot on the map. Then they realize Fluttershy hasn't spoken yet and all look right at her. She then suggests that she stay behind with Spike...only for Spike to reveal that he and Big Mac are going to spend the day talking about "hoofball" (complete with a foam finger and soda hat), which immediately prompts the very feminine and very non-athletic Fluttershy to change her mind.
Everytime Rainbow Dash mentions/hears danger.
Twilight: It could be dangerous...
Pinkie Pie leading the group into the mysterious town.
At Galacon 2014 a Brony talked about the Mane 6's Siblings but forgot the Name of Twilight's Brother while cosplaying as him