This is how Prince Optimus is born goes in Magical Mystery Cure.
[Optimus wakes up to find himself in the realm of the Primes]
Optimus Prime: What happened? Why am I here?
[Primus and Celestia appear]
Primus: Well done, Optimus.
Princess Celestia: We knew you could do it.
Optimus Prime: Primus? Your highness. I do not understand. What did I do?
Princess Celestia: You have did something today that's never been done before. Something even a great unicorn like Star Swirl the Bearded was not able to do, because he did not understand friendship like you do. The lessons you've learned here in Ponyville have taught you well. You have proven that you're ready, Optimus.
Optimus Prime: Ready? Ready for what?
[Primus projects images of Optimus' previous adventures with Twilight]
Princess Celestia: You've come such a long, long way~
And I've watched you from that very first day~
To see how you might triumpth~
To see what you might do~
To see what you've been through~
And all the ways you've made me proud of you~
It's time now for a new change to come~
You've and your new life has begun~
To go where you will go~
To see what you will see~
To find what you will be~
For it's time for you to fulfill your destiny~
[Optimus rises into the air as the Matrix of Leadership starts to glow]
[Meanwhile, the ponies and Autobots are looking for Optimus when his Autobot logo appears in the sky and floats down to them]
Twilight Sparkle: What's that?
Applejack: Optimus? Is that you?
Bulkhead: It had better be.
[When the light fades, Optimus stands there and unfurls his own pair of Alicorn wings and sprouts a horn on his head]
Rest of main cast: [gasps]
Twilight Sparkle: Whoa.
Applejack: Wha... I-I've never seen anything like it.
Bulkhead: Me neither.
Rainbow Dash: Ha! Optimus' got wings! Awesome! A new flying buddy! [laughs]
Rarity: Why, you've become a Prime/Alicorn hybrid. I didn't even know that was possible.
Bumblebee: [beeps] (translation: Me neither.)
Pinkie Pie: Prime/Alicorn hybrid party! [blows party kazoo]
[Fluttershy and Ratchet touch Optimus' new wings]
Fluttershy: Wow... You look just like a prince.
Ratchet: That would explain the wings and horn.
[Princess Celestia flies in]
Princess Celestia: That's because he is a prince.
Main cast: Huh?
Pinkie Pie: Hold on a second!
Smokescreen: Wait. What?!
[Pinkie and Smokescreen drink a glass of water then spit it out]
[Twilight looks at Optimus and hugs him]
Twilight Sparkle: I'm so proud of you
Optimus Prime: A... A prince?
Princess Celestia: Since you've come to Equestria, you've displayed the charity, compassion, devotion, integrity, optimism, and of course, the leadership of a true prince.
[Twilight, her friends, and the Autobots bow before Optimus]
Optimus Prime: But does this mean