Unaired pilot

The unaired pilot is the unofficial pilot of Gravity Falls. It was a low-budget, pre-production test version of "Tourist Trapped." While pitching Gravity Falls to Disney, Alex Hirsch was eventually asked to create a pilot of the series to show to the network. He accepted, and the series was later greenlit for production as a full series. The pilot has never aired on television, but a few clips of it have been uploaded online from various sources.

Official overview
Twins Dipper and Mabel visit their eccentric great-uncle Stan for a summer in Gravity Falls, Oregon, where he operates the the world's most bizarre museum. In the opener, the twins arrive in Gravity Falls and soon discover something amiss in the remote town.

Synopsis
The episode opens with young twins Dipper and Mabel Pines arriving to spend their summer break with their Great Uncle Stan in the remote town of Gravity Falls. Dipper soon finds his sister's new crush is suspiciously odd, which causes Dipper and Mabel to come face-to-face with the town's strange and uncanny secrets. Dipper also finds a mysterious journal with facts and notes about Gravity Falls' creatures that hints to an even greater cover-up hidden within the town's wondrous past and present. Dipper then believes Mabel's boyfriend is a zombie when he starts acting strange. When Mabel is with her boyfriend, he tells her that he is actually a gnome standing on top of other gnomes. Dipper asks Stan if he could use the golf cart to save Mabel.

Dipper takes the cart and finds them in the forest. Dipper questions what the heck is going on, and Mabel explains that Norman turned out to be a bunch of gnomes who are in fact complete jerks. Dipper realizes that he was way off and checks the journal, only to see that there is no weakness listed for the gnomes. The gnomes now have Mabel tied up. Dipper commands them to release Mabel or else. The gnome begins to explain that Dipper won't be able to stop them because they are a powerful race, but Dipper stops him in mid-sentence and chucks him with the shovel. The other gnomes then grab Mabel and run away with her.

Once Dipper realizes that the gnomes are getting away with Mabel, he gets in the car and starts to chase them. The other gnomes in the forest jump off the trees and start tearing the golf cart, then the gnomes are fired like arrows by a bow towards the golf cart, Dipper dodges them though. Dipper soon catches up with the gnomes. Once he does, he whacks the gnomes carrying Mabel away with the shovel, and unties Mabel and drives away from the gnomes. The gnomes form a giant monster and starts to chase the car. Dipper drives the car through a Gravity Falls bilboard off a cliff, crashing the cart in front of the Mystery Shack. Dipper and Mabel crawl from the cart. Dipper warns the gnomes to stay back. He throws the shovel at them, but they smash it to the ground.

Mabel then tells Dipper that she has to do it. Dipper doesn't agree, but she tells him to trust her. Mabel agrees to marry the gnome, Jeff. Jeff is excited and goes to put the ring on Mabel's finger. Once Jeff successfully places the ring on Mabel's finger, he wants to hurry and get Mabel back to the forest, but Mabel says that he must first kiss the bride. Jeff puckers up, but to his surprise, Mabel has a leaf blower pointed his way. Mabel sucks and shoots Jeff out of the leaf blower because he lied to her, broke her heart, and messed with Dipper. As he is flying through the air, he says that he'll get them for that. The rest of the gnomes are confused as to what they should do next. Mabel then begins blowing them with the leaf blower, forcing them all back into the forest. One of the gnomes gets caught in the plastic from a 6-pack soda and is carried away by a goat. Mabel feels sad that her first boyfriend was a bunch of gnomes, so Dipper tries to cheer her up by saying that her next boyfriend will be a vampire.

Dipper and Mabel knock on the door of the shack, Stan answers covered in melted red popsicle stains and he says "brains" because he has brain freeze, Dipper and Mabel think he is a zombie, and they throw rocks at him. Mabel is then seen jumping on the bed, playing with her toy while Dipper writes about the events that happened that day in the mysterious journal he found. Dipper explains what mysteries are waiting to be uncovered and supposedly the next day Dipper is seen running away from a U.F.O.

Trivia

 * The pilot was animated by House of Cool studios, located in Toronto, Canada.
 * It is 11 minutes long, approximately half the length of a normal Gravity Falls episode.
 * Alex Hirsch stated that he hopes this pilot isn't ever fully shown to the public, because it's a mess and it would be like showing his awkward high school photos.
 * The pilot was likely created during 2010.

Differences

 * Unlike the episode "Tourist Trapped ," Dipper has his blue pine tree hat throughout the entire episode, instead of him getting it in the end.
 * Stan appears to have a supreme fondness for popsicles.
 * Wendy and Soos did not appear in the pilot episode.
 * There are, of course, noticeable differences in style and character designs. The following are key differences.
 * Details are not as heavily outlined as they appear in the show's current design.
 * Dipper has no vest, and has white shoes.
 * Mabel has a different outfit, and also has white shoes.
 * Stan has four fingers in the pilot while in the series he has five. Also, Stan has grey eyebrows and no noticeable hair on his head, but thick white hair around his head in the pilot. His fez has a star between the claw-like points and Stan's nose is a different shape, instead of the drop shaped nose he has in his final design.