Party Pooped - Pinkie's Trip · 5:20pm Jun 30th, 2015
It was a heroquest.
As the Trickster of Twilight's Ring, she went questing for a solution to the yak problem... and won through by accidentally and humorously defeating herself at the brink of conventional success. She was probably physically tripping out on cake frosting somewhere.
She was hopped up on LSD in her cellar base behind some balloons. She was woken up by her friends coming in and talking about her. Everything else was the acid talking.
The Yaks declared war on Griffons next. They were all eaten. No, I didn't like the episode.
My SO and I thought that the authentic yak sled she rode back on was going to be the "item from home" that won the yaks over.
The other thing is if you notice it's made clear that despite seeing it everything after the stagecoach falls off the cliff is a story Pinkie tells Cadence. In fact the story may have started well before that. We know Pinkie isn't a reliable narrator, unless "and that's how Equestria was made" makes sense with her cutie mark story. On the other hand it is Pinkie so if anyone could get on a sled countless miles away and slide all the way back home after falling down a hill it would be her. I mean she slides up her slide somehow, and Fluttershy points it out, even though she's seemingly forgotten she can fly again. In fact Im 90% sure she was even airborne when she wondered about getting up. Though it is Equestria so even though it seems ridiculous maybe even the Beetles joke actually happened, complete with the stallions growing out their manes and beards at a silly rate and everything else suggesting a great amount of time had passed.