Rescuing Yuna and her friends/Escaping the Mummies' Tombs

Here is how Princess Yuna and her friends are being rescued in Welcome to Horrorland.

Later, Yuna and her friends are being chased by a bunch of Skeleton tigers.

Princess Yuna: Come on! Hurry!

Honker Muddlefoot: Yuna! Wait for me!

Just as they ran as fast as they could, It was a dead end.

Huey: We're trapped!

Dewey: Trapped like rats and mice!

Dipper Pines: Okay. Any last words before we became tiger food, Guys?

Mabel Pines: (notice someone) Jack Skellington!

Dipper Pines: Jack Skellington?

As Mabel pointed, Jack Skellington came to the rescue.

Jack Skellington: Hello, Little friends.

Princess Yuna: What're you doing here, Jack?

Jack Skellington: Jonathan Chiller send me a message to save you all. Right, Zero?

Zero: (barks)