Here is how Princess Yuna discovered the Indominus Rex and became a tamer to the animals in Genesis World.
At the I-Rex paddock, Orange Bloom is showing Yuna and her friends around Genesis World.
Orange Bloom: This is the Paddock of the very first dinosaur hybrid called. Indominus Rex. The name means Fierce or Untamable King.
Orange Cake: You mean the one from Jurassic World, Aunt Orange Bloom?
Orange Bloom: (chuckles) That's right, Orange Cake.
Armor Bride: The Indominus Rex?
Sweetie Heart: What is this thing made of?
Princess Flurry Heart: And what's it half what?
Orange Bloom: She is half T-Rex, The other halves are the Velociraptor, Carnotaurus, Giganotosaurus, Majungasaurus, Rugops and Therizinosaurus and the two modern animals, The Cuttlefish and the Tree Frog.
Princess Yuna: I remembered that! (looked at Journal 4) Indominus Rex, I've been reading all about it.
Snowdrop: I've heard about it too.
Princess Yuna: The servants of the Darkness had a couple of Indominus Rex of their own while Sméagol, My friends and I are getting close to Armageddor.
Sunburst (Human): Technically, Some of your friends before Jennifer and the others.
Lisa Simpson: I've red about it too, Yuna.
Nyx: What's her name?
Orange Bloom: We've named her "Dawn".
Orange Bloom: It was the name that was given by Lilliana and Radcliffe while creating his own theme park after she hatched.
Lisa Simpson: Are you getting this, Sherman?
Sherman: I sure did, Lisa.
Yuna stared at Dawn inside her enclosure, She was growling and staring at her with her own eye.
Princess Yuna: So that's Dawn.
Princess Sharon: Yuna! Come on!
Twilight Sparkle (Human): Let's go!
Timber Spruce (Human): Pick up the pace!
Princess Yuna: Coming!
Dawn turned away minding her own business, Yuna kept up with the tour.
Meanwhile, Copper was training a pack of Velociraptors with a pig running like crazy.
The Velociraptors, named Charles, Douglas, Donna and Paula were chasing the pig.
Pig: (oinks running for it's life and ran into it's pen)
Copper: Yee-Haw! (give each raptor fresh ham piece) Good boy, Charles. Good boy, Douglas. Good gal, Donna. Good gal, Paula. Y'all consider yourselves lucky to earn your privileges on mating season.
Copper gives fresh ham piece to Charles, Douglas, Donna and Paula when he saw Golden Apple.
Golden Apple: Howdy, Daddy!
Copper: Howdy, Goldie! How're ya doing?
Golden Apple: I'm doing great! I'm having fun in Genesis World!
Donna: (spotted Golden Apple waving)
Applejack (Human): Uh-oh!
Herb Muddlefoot: What's all the ruckus, AJ?
Princess Yuna: What're you doing here, Copper?
Sugar Apple: Yeah, Uncle Copper, What's all the ruckus?
Copper: Well, Sugar Apple, Your Auntie AJ and I wanted to surprise y'all when all of you were coming to Genesis World. Radcliffe made me as the best dang animal trainer.
Suddenly, Golden Apple fell off the bridge and into the raptor pen.
Golden Apple: AAAAAAAAAAAAAAAAAAAAAAAAAHHHHHHHH!!!!!
Applejack (Human): Oh no!
Charles: (spotted Golden Apple and begins to charge)
Princess Yuna: Golden Apple! Hang on!
Copper: Yuna! Wait!
Twilight Sparkle (Human): Stop!
Sunset Shimmer (Human): It's too dangerous!
The two ponies ready to shoot the raptors with Tranquilizer Guns, Yuna stopped them when Radcliffe and Ford Pines came to see her and the rest of her friends.
Princess Yuna: Wait! Don't fire! Don't fire!
Yuna was taming the raptor pack while Copper gets Golden Apple out of the pen.
Princess Yuna: Whoa! Hold it! Stand down! Stand down! Charles, Down!
Charles: (stands down)
Princess Yuna: Hey! Hey! Douglas, I see you. Now, Back off!
Douglas: (backs away)
Princess Yuna: Good.
They witness Yuna becoming very trainable with the Raptors, Ford was mostly surprised.
Applejack: How in thunderation....?!
Applejack (Human): Are ya seeing this, Apple Bloom?
Apple Bloom (Human): Dang straight, Sis.
Radcliffe: My word! Are you seeing what I seeng?
Ford Pines: Yes, Radcliffe. Somehow, She was taming them!
Applejack: Golden Apple, I was so worried about you! Are you okay?
Golden Apple: Yeah, Mama. I'm alright. Sorry for scaring you and Daddy.
Copper: At least you're safe and sound thanks to Yuna.
Ford Pines: Yuna!
Princess Yuna: Ford! Radcliffe!
Radcliffe: How'd you do this?
Ford Pines: How're you able to tame those Velociraptors?
Princess Yuna: I don't know, I guess I just know how to be great at taming animals.
Ford Pines: And I thought Fluttershy was great with animals.
Radcliffe: Indeed, (to Yuna) Come with me, I have something special in mind for you.
Princess Yuna: Wow! Really?
Snowdrop: I wonder what Radcliffe had for Yuna.
Mirage the Illusionist (Human): I have no idea.
Gloriasa Daisy (Human): Me either.
Sunburst (Human): What do you think, Max?
Max Goof: I'm sure thing will turn up.
So, Radcliffe took Yuna to the stadium to train some animals.
Soon, Radcliffe was preparing to show the audience Yuna's unique animal taming abilities.
Radcliffe: Mares and Gentlecolts, I give you, Princess Yuna!
Yuna was about to tame a couple of female Smilodons.
Princess Yuna: (raised her hoof) Down, Girls. Settle.
As the Smilodon responded to Yuna, The audience cheered as the show ends.