Gravity Falls

So he said, "Okay, one more season, … Before we started the [second] season, it said in my contract, before I put pen to paper, that this is my last season." The studio agreed, under the condition that Hirsch could not tell anyone.

In an interview with Oh My Disney, Hirsch claimed he already had the beginning, middle, and end of the story for Gravity Falls planned out when he first pitched the series.

He originally thought the series would "be two or three seasons".

However, Hirsch had never created a TV series before and after experiencing how "incredibly draining" it was, he initially wanted to end the series after season one and, ultimately, on a cliffhanger.

Two people convinced Hirsch to return for a second season: Jon Stewart, who shared that his kids loved the show, and Over the Garden Wall creator Patrick McHale.

McHale had been watching the series and told him: "Look, after that cliffhanger, you've got to finish it." Hirsch decided that he had about ten more episodes left in him, so he went to the network, who said, "We only take seasons in twenties".