This is how Equines meet Optimus Prime goes in Darkness Rising Part 1.
Bumblebee: [beeps] (translation: Wanna take a ride somewhere?)
Rainbow Dash: I think he wants us to get in.
Rarity: No, just me.
Rainbow Dash: What?
Rarity: Yours is over there, darling.
[Rainbow Dash turns and looks at Arcee. Nearby, an orange, blonde mane Earth Pony named Applejack is drawing a picture of Arcee]
Applejack: Coolest. Bike. Ever.
[She gets a text]
Applejack: Again? Ignore.
[She sees Arcee driving away with her holographic driver]
Arcee: Relax, I just wanna talk to you.
Rainbow Dash: Don't you mean you and your new friend?
Arcee: Kid, there's a lot you don't understand.
Rainbow Dash: No, I get it, I get it.
Arcee: The first rule of robot fight club is you don't talk about robot fight club.
Rainbow Dash: What you need to understand is that I don't want a bunch of crazy talking vehicles following me around trying to get me killed!
Arcee: Look, Rainbow Dash, is it? Your personal safety is exactly why Optimus Prime has requested your presence.
Rainbow Dash: Optimus who?
Arcee: You may be in danger because you are one of the few one of the only six who have ever seen us.
Applejack: Sugarcube, what are you waiting for? Go with!
Rainbow Dash: And why exactly are we taking her?
[At Autobot Outpost Omega One]
Ratchet: I thought they were two.
Arcee: Haven't you heard? Equines multiply.
Rarity: I am Rarity.
Applejack: I am Applejack.
Rainbow Dash: I'm Rainbow Dash
Pinkie Pie: [gets in Smokescreen's face] Hi, I'm Pinkie Pie. And I get super-duper excited about everything all the time.
Fluttershy: I... I'm Fluttershy.
Twilight Sparkle: And I'm Princess Twilight Sparkle.
Bulkhead: I'm Bulkhead.
Arcee: Arcee's the name.
Ratchet: I'm Ratchet.
Bumblebee: [beeps] (translation: I'm Bumblebee.)
Smokescreen: I'm Smokescreen.
Optimus Prime: And I am Optimus Prime. We are autonomous robotic organisms from the planet Cybertron. Also known as Autobots.
Twilight Sparkle: Why are you here?
Optimus Prime: To protect your world from the destruction that was done to our own.
Optimus Prime: Twilight, you will be under my supervision.
Twilight Sparkle: Why?
Optimus Prime: Because I am going to be your guardian.
Twilight Sparkle: I would love that.
[Then a police siren is heard and everyone sees a black cop car drive up]
Bulkhead: So Mal's back?
Arcee: About time, too.
[The cop transforms into the Autobot Shapeshifter, Major Malfunction]
Major Malfunction: I heard about Cliff. Is it true? Did the Cons really scrap him?
Twilight Sparkle: Who's this?
Optimus Prime: This is Major Malfunction, our loyal Autobot trainer.