Other than the film's title, there are no opening credits
During the credits, the Friendship Festival continues in a "pointy-art" style. Also, there are small gags like Pinkie doing a kick line with the Queen of the Hippos, the remains of the Storm King somehow dancing, and Angel Bunny bopping with Fluttershy's bird choir. Blink and you'll miss an appearance by Discord in the crowd.
After the credits end, Princess Celestia makes one final appearance to raise the sun.
Gummy the alligator, a couple of baby Hippogriffs, and Shelly and Sheldon play with the scrolling credits.
During the credits, Derpy Hooves makes one last appearance, trying to catch a muffin (her favorite food) in the air.