Lil Gideon

Gideon Charles Gleeful, better known as his stage name, 'Lil Gideon is a proclaimed television psychic and the most recurring antagonist of the Disney Channel TV animated series, Gravity Falls. He made his debuting in the episode, The Hand that Rocks the Mabel as the main villain. He is the owner of the Tent of Telepathy and has an obsessive crush on Mabel Pines. He also holds an extreme grudge on both Dipper and Grunkle Stan for preventing their date.

Histroy
The twins, Dipper and Mabel, both witness a television commercial promoting the "Tent of Telepathy", claiming that the owner of the tent, Lil' Gideon possesses psychic abilities, particularly in mind-reading. Despite the fact that Grunkle Stan forbids them from going due to Gideon being a rival business competitor; the twins, along with Soos, visit the tent to test Gideon's authenticity.

During the show, Gideon notices Mabel in the audience and confronts her the next morning, asking is she wants to join him at his dressing room to perform makeovers, an offer to which Mabel agrees. Eventually, however, Gideon expresses his love for Mabel, stating that he wants to be more than just friends, but Mabel, on the other hand, does not quite feel the same for him. She reluctantly agrees, as long as it were to be only one date.

At a local restaurant, however, Gideon, through the help of a macaw, proposes another date in the presence of restaurant spectators, leaving Mabel no choice but to accept. Stan, disapproving of the engagement after hearing about it, decides to talk to Gideon's father, Bud Gleeful, to call off the marriage, but Gleeful agrees to give a lot of money to Stan if Mabel and Gideon are both engaged.

Dipper soon realizes that this is beginning to present a problem for Mabel and offers to discuss the situation and Mabel's breakup to Gideon in private. Although Gideon manages to suppress his anger towards Dipper during this, he is convinced that Dipper is purposely getting in between their relationship and begins to plot his revenge. He calls Toby Determined, a journalist for the Gravity Falls Gossiper, and gives him Shandra Jimenez's phone number, a news reporter whom the journalist has a crush on. In exchange, Toby calls Dipper, getting him to go to Gideon's factory, where Gideon nearly kills Dipper with a powerful amulet, which gives him his pyschich abilities, including telekinesis. However, Mabel shows up, formally breaks up with Gideon, and uses the amulet to defeat him, but spares him.

Afterwards, Gideon is seen plotting his revenge with a wooden playset of the Mystery Shack, complete with miniature version of Dipper, Mabel, and Grunkle Stan. It is then revealed, like Dipper, that he owns a mysterious book of his own, but marked with the number two, instead of three.

Gideon makes his next appearance in "Irrational Treasure". He dresses up as a tomato farmer (As he puts it: "A humble tomato farmer, selling his wares!") on Pioneer Day and teases Stan by throwing tomatoes in his eyes after he insulted Gideon by saying he looks less girlier than usual. He is also the main antagonist of the episode, "Little Dipper" where he plans to shrink Grunkle Stan so that he can become bigger, but was ultimately foiled by Dipper and Mabel when they tickle him, causing him to be rolled right away from the Mystery Shack.

He is the main antagonist of the episode, "Dreamscaper" where he summons a pyramid demon named Bill Cipher in order to figure out the combination to Stan's locker so that he can get Stan's deed to get the Mystery Shack from him. Bill was nearly successful in getting the deed but lost it in the bottomless pit memory. This causes Gideon to call off the deal of Bill getting money from him, causing Bill to get upset and turn into a giant to try and get Mabel, Soos, and Xyler and Craz, but with Dipper's help, they are able to defeat Bill. Dipper realises what Stan meant to him and they embrace with Dipper giving a short friendly neck hold to Stan. Unfortunately, this moment is short lived, as Gideon had successfully taken Stan's deed to the Mystery Shack, via blowing up the safe and half of the shack with dynamite, and then getting his dad to drive a wrecking ball with Gideon on it laughing evily as Bud uses the wrecking ball to destroy the Mystery Shack and claim it for himself and his son Gideon, leaving the episode on a cliffhanger.

In the season 1 finale episode, "Gideon Rises," he is the main antagonist, and has now taken the Mystery Shack claiming he plans to turn it into Gideon Land. However he really plans to find the first Journal which he belived was hidden somewhere in the Mystery Shack. Dipper and Mabel try to go home, but Dipper tries to call in the Gnomes to stop Gideon, but Gideon uses a whistle to hurt the Gnomes's ears and cause them to get Dipper and Mabel out of his sight. In the process, Gideon takes Dipper's book #3 and taunted Dipper claiming without the book he was nothing. Dipper and Mabel have no choice but to go back home. After seeing it was the third book and not the first as he assumed, he gets furious after figuring out that he needs all three books in order to go to an alternate dimension. Assuming that Dipper has the 1st book, Gideon gets on a giant Gideon robot powered by motion capture that Old Man McGucket made to try and track the twins down. He tries getting them, but Soos now a bus driver was somewhat able to avoid him. Dipper and Mabel are now on the edge of a cliff, and manage to escape on to the mine cart tracks. Gideon then uses the robot to hurt Dipper and kidnap Mabel in order to force her to become his queen. Dipper at first gives up, but then charges toward the Gideon bot, he smashes through the window used as an eye and attacked Gideon from the inside. Although Gideon first fights back, Dipper manages to overpower him, however as Gideon was still hooked to the robot, it replicated his fight as such it knocked the robot off the tracks sending all three of them toppling off the cliff into the ground. Fortunately, Dipper and Mabel survive when Mabel uses her grappling hook to hook on to a tree branch. Gideon also survives, and tries to get Sheriff and Deputy Blubs and Durland to arrest the twins, but Stan arrives and shows the Gravity Falls residents that Gideon's psychic abilities were fake, revealing Gideon's buttons he had given out were really secret camera's so he could spy on everyone and convince them he was psychic, causing the residents to turn on Gideon. Also, Blubs and Durland arrest Gideon and take him to jail and Grunkle Stan gets the Mystery Shack back and the twins are able to stay with him. At the end of the episode, Stan is revealed to have the book marked with the number one, and gets all three books to open a portal to an alternate universe. Before Gideon was sent to jail, he swore to the Pines family that he will be back for revenge.