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The second half is broadcast as "Weirdmageddon 4: Somewhere in The Woods" in subsequent re-airings for half-hour programming.
Gravity Falls is heavily inspired by Twin Peaks, and Alex Hirch actually wanted David Lynch to do the voice for Bill Cipher. This did not pan out, but he was able to have one Twin Peaks alumnus on the show, Kyle MacLachlan (Agent Cooper). He voices the bus driver.
The creator of the show, Alex Hirsch, teared up writing the final scene for this episode.
On November 20, 2015, creator of the show Alex Hirsch announced that the second season of the show would be its last. Hirsch made the decision in order for the show to not lose its original spark. The show concluded with a one-hour special event titled "Weirdmageddon III: Take Back the Falls".
The series finale of Gravity Falls because Alex Hirsch wanted to wrap up the madness and make it end the way he wanted.
The way Rumble McSkirmish disappears after the battle with his thumb up is a reference to Terminator 2: Judgment Day (1991).