Bill Cipher

"Remember, reality is an illusion, the universe is a hologram, buy gold, bye!"

- Bill Cipher Bill Cipher is the main antagonist of Gravity Falls. He is a Dream-Demon with mysterious motives, and seems to have a vendetta against the Pines family, especially Stanford Pines.

Background
Bill is an age-old demon who hails from the 2nd Dimension, a place that is described by Bill as a "flat world with flat minds and flat ideas." Determined to spread chaos and destruction, Bill "liberated" his dimension by destroying it. Eventually, he found his way to the Nightmare Realm. In this dimension, Bill had no corporeal form, so he could only access or possess the minds of humans. With this ability, Bill manipulated countless humans so that he could find a way to enter the 3rd dimension in physical form and liberate that dimension as well.

Bill's interactions were recorded throughout the history of humanity, including ones with natives who lived in what would become Gravity Falls, Oregon. The people discovered that Bill was too dangerous and found a way to defeat him using a zodiac with ten symbols. The people left behind a painting of their encounter with the demon, including how to summon him and a warning never to read it. Stanford Pines would discover this symbol in the late twentieth century when he came to investigate the town, hoping that it would help him in his research on Gravity Falls' anomalies. After a failed attempt to summon the entity, Ford ended up encountering Bill in his dreams, where Bill offered to help answer Ford's questions of the universe to gain his trust. Ford, blinded by this flattery, agreed to the deal.

Bill then had Ford build a machine he claimed would benefit mankind, but in reality was a portal for the demon to enter the 3rd Dimension. However, one of Ford's human friends, Fiddleford McGucket, discovered the true nature of the portal and warned Ford before completing it. Horrified and betrayed, Ford shut down the project and hid the instructions on how to operate it, shifting to working on countermeasures in case the demon returned. Bill, however, patiently boded his time for the portal to reactivate.

Sightings
Before his debut in "Dreamscaperers", Bill appeared frequently in Gravity Falls. He was an unseen character who wrote the cryptograms in the online game Rumble's Revenge. His name and existence is deduced by taking all the capital letters in the cryptograms from Rumble's Revenge, which forms the sentence: "MY NAME IS BILL."

A picture of Bill shows briefly at the end of the opening theme. This is partially an image from his entry in book 2. Encircling him are various symbols that can link to various characters in the show. Most notably, when he appears physically for the first time, he refers to Dipper, Mabel, and Soos, as "pine tree, shooting star, and question mark" respectively. The entry also makes special note of his association with the glasses symbol. It also says, "This old triangular being has appeared in my dreams every night for weeks."

In book 3, the text says "Why is he watching me?" and "Bill has proven himself to be one of the friendliest and most trustworthy individuals that I've ever encountered ... life. What a guy! I honestly ... him more. Not evil ... Bill is a true gentleman." However, the second part is crossed out in red ink. On the next page is "DO NOT SUMMON AT ALL COSTS!" in red block letters, the rest of the page splatted with a dark red substance.

Physical appearance
Bill is a triangle with a pyramid design, therefore resembling the Illuminati, with an eye in the middle. Among the bottom part of his body is the a brick pattern. In the theme song, Bill has a top hat on, a bow tie, and stick arms and legs, but lacks them in most of his cameos. As a metaphysical demon, Bill is capable of altering his body into a variety of frightening and cubic forms. While he can manipulate his body at will, wounds on Bill seems to suggest his inside has an organic, flesh-like texture.

Personality
Bill, quite simply, was a master manipulator able to adapt, manipulate and deceive others through the use of flattery, promises, mind control or dealings throughout making himself and his objective a mystery. Despite his insane and sadistic ways, Bill was affable, if not obnoxious, to other, but this is only one of the many facades of his unpredictable personality; he is willing to betray, lie and submit others to a life of misery and torment for his own amusement and shamelessly go back on his deals (whilst technically keeping his promise) through his word lineage and manner of phrases. At times, Bill displays a murderous temper, though seldom seen, it causes his voice to become deep and guttural, accustom to many beliefs of demonic figures. He also appears to be aware of his insanity as when Gideon states him as such he shrugs it off, asking what his point was.

Bill also had a dark and rather sadistic sense of humour. This is displayed during his joyous and maniacal laughter in the face of other peoples and his own pain, such as ripping the teeth out of a deer and presenting it as a gift to Gideon, switching around every hole on Northwest's face and was after taking control of Dipper's body, described "pain as hilarious" whilst continuously self-harming, showing he was also masochistic.

Despite his treacherous nature, Bill does have a (twisted) sense of honour. He will follow through on deals and keep his word, assuming if he in the mood for it but strongly prefers the immoral way and largely feels no incentive or debt for anything. Gratuitously, he allowed Gideon control over Gravity Falls after he took a physical form and control of the world. Outside of this, Bill displayed a willingness to go against his own rules, preparing to invade Ford's mind without his consent, before being reminded that he cannot do that without engaging a deal with the person. He is not above torture or blackmail to obtain what he wants such as attempting to force Ford to accept his deal through intimidation and threatening to murder Dipper and Mabel if he did not consent. Ironically, Bill's backstabbing ways left him oblivious to a double-cross from the Pines twins, resulting in his defeat.

Role in the series
"Dreamscaperers" is the first time Bill is directly addressed and introduced in the series. Gideon Gleeful, in an attempt to take over the Mystery Shack once again, summons him. Gideon tells him to steal Stan's safe combination directly from his head, so that Gideon can steal the Shack's deed. Bill immediately agrees once he pictures Stan's tattoo, but in return Gideon would have to help him in his own plans. We don't know what they are yet, but they might have something to do with a secret society which Stan could possibly be included in. Gideon agrees and the two shake on it. Unbeknownst to Gideon, Mabel and Soos witnessed the deal in the forest, and get Dipper's help to follow him into Stan's mind.

Once inside Stan's head, Bill confronts the trio and brags that he knows what they're all thinking. To prove his statement, he summons Xyler and Craz from Mabel's imagination. He tricks Mabel and her two dream guys into looking for the memory of Stan's safe combination first, knowing they would lead him straight to it. At some point, Soos is separated from everyone else, and Bill takes his place. Once they find the correct memory he takes it and nearly escapes with it. But while he was reading out the combination to Gideon (whom he was connected to), Mabel shoots the memory into another memory of the Bottomless Pit with a nyarf gun. Gideon breaks off their deal to Bill's fury, and he turns his anger onto Mabel and Soos, bringing their worst nightmares to life, and killing Xyler and Craz.

Dipper returns in a timely manner and tells Mabel and Soos that while they are in Stan's mindspace they can do whatever they want. The three battle Bill and he is nearly defeated, but puts a stop to everything instead. Impressed, he decides to let the three go, and warns them about a mysterious darkness that will change everything before telling them he will be watching them. Leaving one last impression of the wheel that encircles him in book 2.

Bill reappears again in "Sock Opera" for the first time in season 2, when Dipper is trying to figure out the password for the laptop from the former episode, "Into the Bunker". He offers the laptop's password in return for the favor he wants, but Dipper refuses the offer. Later, at the moment the laptop is on countdown for complete data erase after too many failed password entries, he appears again and Dipper accepts the deal of trading a puppet to obtain the password. Bill takes over Dipper's body as his "puppet" and destroys the laptop.

He then follows Mabel to her puppet show in pursuit of Dipper's journal that is being used as a prop in the show. After Mabel has been informed of Dipper's body having been stolen by him, he finds her with the journal as she is retrieving it for Dipper. He almost swindles her out of it but ends up in a fight with her. He ends up losing because Mabel uses Dipper's physical weakness and exhaustion to her advantage. As he collapses, he is thrust out of Dipper's body. Bill possesses the Dipper puppet afterward and says that he will return. However, Mabel lights the pyrotechnics, which destroy the puppets.

Bill briefly appears in Ford's dream during the episode "The Last Mabelcorn", warning him about the end of the world that is coming. In this episode, it is revealed that Bill originates from an alternate dimension known as the Nightmare Realm.

He appears again in "Dipper and Mabel vs. the Future", where he possesses Blendin Blandin and tricks Mabel into giving him the Interdimensional rift, which he eventually destroys, beginning the end of the world. Bill then takes on a physical form and begins wreaking havoc on Gravity Falls. He traps Mabel in an enormous bubble, melts the statue of Nathaniel Northwest, and introduces his friends, an assortment of monsters as terrifying and weird as Bill himself. After Ford Pines attempts to blast the dream demon back into his own dimension, Bill turns him into a golden statue to use as a backscratcher, and destroys the three journals.

In the series finale "Weirdmageddon", Bill discovers his inability to leave Gravity Falls even after entering the real world. To find a way out, Bill tries to get into Ford's mind, but Ford refuses to let him in. After capturing the kids and coming very close to killing them, Ford caves in and lets Bill into his mind in exchange for Stan and the kids lives. Bill enters his mind only to find that Ford switched places with Stan and now Bill is in Stan's mind. Before Bill can escape, Ford starts erasing Stan's Memory, causing Bill to deteriorate in glitch-like fashion inside the mindscape as Stan punches and shatters Bill into pieces, destroying him and forever ended his evil game.

Trivia

 * He is based on the Eye of Providence, which is most commonly seen on the back of an US $1 bill.
 * On the page about Bill in book 2, the -$12 bill says "Semper vigilantum", which in Latin means "always watching".
 * Bill mentions gold (and Stan mentions burying gold in "Boyz Crazy"). The Beale ciphers are a set of three ciphertexts, one of which allegedly states the location of a buried treasure of gold, silver and jewels estimated to be worth over USD$63 million as of September 2011.
 * He may also be related to the Illuminati, a figure on the Mayan Calendar and subject of innumerable modern conspiracy theories.
 * It is unknown what he wanted in return from Gideon when he got the safe code from Stan's memory.
 * Both Gideon and Dipper's journals contain sections on Bill, but curiously, Gideon's journal contains instructions on how to summon Bill, whereas Dipper's contains instructions on how to stop Bill if he is summoned.
 * In the game Rumble's Revenge, one of the translated cryptograms says "i will be returning to gravity falLs …………" This foreshadows his appearance in "Dreamscaperers".
 * He unofficially appeared as a pop-cultural cameo in an episode of the adult cartoon Rick and Morty.
 * Bill's wheel symbol makes a cameo in Disney Infinity 3.0 Edition.
 * According to Alex Hirsch, Bill's full name is Bill Mischief Cipher.
 * After the credits, a real-life model of Bill's petrified body  is mysteriously shown.