Here's how the new island and Ernie's appearance goes in Ernie the Dragon Hunter.
[we see Nightstar flying through the sky with Yuna and Biran riding her]
Brian: Alright, let's do this.
Yuna: Brian, this isn't a good idea.
Brian: Come on, Yuna. where's your spirit of adventure? It'll be fine. [leaps off] WHHHOOO HOOOOOO!!!!!! YEAH, BABY!!!! Time for a test drive.
(Brian then pulls a rope and deploys a flight suit!)
Brian: Yes, it works! I'm a genius! I'm gonna be called... [slams into a tree and falls off]
[she and Nightstar then fly down]
Yuna: Are you okay?
Yuna: [helps him up] Brian, I think that if we're going to test your flight suit, we should do it away from trees.
Brian: Yeah, this makes a 4th island discovered.
Yuna: Let's see what we have on this island.
[Brian and Yuna then journey through the island]
[Later it fades to a dock]
(we then see a stallion walking along the dock till he bumbs intro someone]
Stallion: Dear friend, I'm sorry to hit you.
???: [chukles] He apologized. What is it who hit you? Oh, it's just a equine. I am no friend. I am Ernie, the Dragon King. [reaches to his lightsaber] And you'll be loyal, to ME! [cuts off his head]
[he then puts away his lightsaber]
Erine: [catches his head] [evil laughs]
Princess Celestia: [moaning]
Princess Luna: [comes in] Tia, is something wrong?
Princess Celestia: I'm having a terrible feeling. Something bad is out there.
[Just then Brian sees some 2 talking]
Brian: Hey, what's going on?
Stallion: Haven't you heard? A stallion was killed by a giant chicken.
Brian: A giant chicken? [he then realizes who they mean] Oh, no.
[It cuts to him running]
Brian: PETER! LOIS! CHRIS! STEWIE! MEG! VINNY! HE'S BACK, ERNIE'S BACK!!!! [crashes into a table]
Vinny: Dude, what's wrong?
Brian: Ernie the Giant Chicken... is back!
[Everyone is shcoked]