Characters making faces
Derpy is not the only pony known for making silly faces. Characters in Friendship is Magic also tend to contract this common symptom during strange occurrences, or sometimes intentionally.
Simon says...put your hands on your nose!
"Did someone just...compare ME to Gary Oak!?"
Silly Pinkie Pie. You're not a cat.
This jaw drop = PRICE...LESS!
Hey Rarity, Lily just called! She wants her face back!
This is so wrong on so many levels.
Twilight, still being her usual self.
"So... much... bad... news!"
"Behold! Twilight's new face!"
Looks like Princess Luna is entering the Avatar State.
"Whoa, what you got there?"
That scepter will never become an overused meme. Right?
Spike: still making the same face when burping out a letter.
She's about to sneeze, guys.
Don't hug Rarity too hard, Fluttershy.
"Okay, yeah. I'm totally scared."
"Where did you go, Rarity?"
Dang, what an abusive castle.
"Rainbow Dash, where are you?"
"Please stop torturing me, castle. I beg you."
And then Fluttershy was traumatized.
"What did you put in my drink?"
Rainbow Dash, showing her inner horse.
Rainbow, you're creeping me out...
This is just one of the many faces Ms. Harshwhinny makes in the first act of the episode.
Stop it! We had enough weird expressions for one day!
Scootaloo, are you really sure you wanna fly?
Rainbow is just so happy, her mouth looks weird.
"This comic book is stretching my face!"
"Well, this has been quite the mane-raising experience."
"Can I show you my derp?"
"Heh, so Rarity can do that
"Now get me some coffee!"
Why does mah mouth look like this?
Big Mac is staring into your soul.
This is not the biggest grin Pinkie has ever made.
Pinkie makes a duckface. Your argument is invalid.
You're gonna see a lot of Bulk Biceps here.
Silly Rainbow, you're not Bulk Biceps.
"These dresses are awesome!"
"I'm just drinking water here! I swear!"
Even when faking an injury, she still can make faces.
"You sick? Why don't you eat mah hoof?"
"Why can't I go through this door?!"
Looks like Spikabuse is still alive and well.
"Twilight, you've made me feel dizzy..."
Look out, he's about to sneeze!
Does this look like a face of trouble to you?
You sure you don't want to go to the doctor?
Don't hug Discord too hard, Pinkie.
"Aw, you ponies look so adorable!"
"I will infect you guys with the blue flu for plot conveniences."
"Well, at least you guys have a shield."
Even Discord's stomach has mastered the art of eye derping.
"What a satisfying sneeze."
Shut your little mouth, Rainbow.
"Are you alright, Pinkie?"
"Why are you watering the ground?"
"Am I doing this watering thing right?"
Scrunchy face: the sad kind.
Best face of Season 4. Period.
Now that's one menacing face!
Pinkie has a small mouth. Your argument is invalid.
A goof off? More like a face off!
"Look at me! I can make faces!"
"Behold! Rainbow's new face!"
"Can you make a grin as big as mine?"
Pinkie is a literal airhead.
"Look at me! Ah'm countray!"
Um, are you sure picking noses is actually country-like?
"I love being covered in mud!"
"Can you derp your eyes as much as I can?!"
"That bowtie needs some serious tightening."
Don't try to make us sympathize with Angel, DHX.
Are you lying, Fluttershy?
"Is this the face of evil to you?!"
Stop it, Pinkie. Just stop.
Don't make that face, you spoiled little brat.
"Why do I have to be Diamond Tiara's butler?"
Looks like the duckface epidemic has taken Scootaloo.
"This is how silly you look."
"Can't... take... the cuteness!"
"Can't... take... the cuteness!"
You don't look so good, Apple Bloom.
Your freedom is interrupted!
"Shut your little mouth, Sweetie Belle!"
Are you lying, Sweetie Belle?
"Are you hypnotized yet?"
That is one terrified filly.
Pinkie, don't bite Rainbow's tail! That's Applejack's thing!
Hummingbirds make Pinkie happy all day, it seems.
Well, that's one way to drink cider.
"You're not into winning?!"
Thir ah tho many thhiny thequinth on ma tung.
You have some work to do.
"That was one freaky nightmare."
"My sister's in Canterlot!"
#ThatAwkwardMoment when Lyra held her score upside-down.
Rainbow has the weirdest grin right now.
Twilight is totally speechless at how wrong Rainbow was.
Now that's what I call adorable.
All play and no work make Twilight an angry mare.
An extra "woo" makes everything better.
"Can't take all these costumes!"
Keep grinning, Twilight. Keep grinning.
Rainbow.exe has performed an illegal operation and must shut down.
"There are male adults watching this show?!"
"Did you kill somepony, filly?!"
Draw me like one of your French hens.
Aww, how could you say "no" to these faces?
"Must... get... that... book..."
Well, I guess that's a no, then.
A Pinkie Pie duplicate in a scene edited from Too Many Pinkie Pies
for a commercial, with Fluttershy and Rarity in place of another Pinkie Pie duplicate