Bill Cipher

Bill Cipher is a triangular dream demon, formerly existent only in the mindscape before succeeding in gaining access to the real world. He has been running amok in Gravity Falls, Oregon since being summoned by Stanford Pines over thirty years ago, and is also known for his mysterious demeanor and sadistic humor. Bill is the main antagonist of Gravity Falls, although he doesn't play a central role in the series until the penultimate Season 1 episode "Dreamscaperers".

Before Gravity Falls
Trillions of years prior to the events of the series, Bill Cipher originated from the second dimension. Bill despised living there, describing it as a dimension of "flat minds in a flat world with flat dreams." He "liberated" his dimension by plunging it into burning chaos, along with everyone he'd ever known, including his own parents. He eventually took over a boiling, shifting intergalactic foam between dimensions: a lawless, unstable crawlspace known as the Nightmare Realm. Unfortunately, due to the Nightmare Realm's lawlessness and lack of any consistent physics or rules, it was fated to collapse into itself eventually. After coming to learn of a prophecy that stated he would merge the Nightmare Realm with the third dimension, Bill started coming into contact with humans to accomplish this.

Without a physical form however, Bill could only access the dreams of the third dimension's beings. In order to make his dealings with mortals easier, he took on the name "Bill Cipher" as his real name would "evaporate one with an expression of horror and ecstasy on their face". Among his targets were the natives who lived in what would become the town of Gravity Falls, Oregon.

Bill once asked a local shaman named Modoc the Wise to build an interdimensional gateway to the Nightmare Realm, but the result was made out of twigs. When Modoc learned of the prophecy that foretold of an apocalyptic event that would stem from interactions with Bill Cipher, he lit himself on fire in an effort to avert it.

The natives eventually discovered a way to defeat Bill by using a zodiac with ten symbols. They left behind elaborate cave paintings about their encounter with the demon, including how to summon him, and more importantly, a warning never to read the incantation that would summon Bill aloud. The valley was deemed a "cursed land" by the natives, who evacuated around 1000 AD. The area would eventually be rediscovered by Quentin Trembley and repopulated by pioneers, giving rise to the town of Gravity Falls.

In the late twentieth century, a young man named Stanford Pines, who had spent the past six years investigating the town's plethora of unnatural creatures and oddities, hit a roadblock in his research and was left without answers as to how the improbabilities of Gravity Falls had come to be. During the roadblock, he uncovered the ancient cave containing the ancients' stories of Bill Cipher. Heedless of the warnings, Ford repeated the incantation aloud, summoning Bill into his mindscape. Bill recognized Ford's brilliant but cocky and insecure nature and his near-friendlessness as ideal conditions for manipulation, choosing to introduce himself to Ford as a muse who chose one brilliant mind every century to inspire.

It was Bill who revealed to Ford that Gravity Falls' weirdness was caused by a rift between dimensions, through which the other side's weirdness leaked through. With Bill's assistance, Stanford drafted blueprints to create an inter-dimensional gateway beneath his home, and recruited his college friend Fiddleford McGucket for assistance. As Bill and Ford's partnership seemingly grew to friendship, Ford seemed to develop an obsession with Bill's powers, collecting triangular memorabilia such as rugs and statues, modeling his home's architecture in his image, converting his private study into a place of worship. He even allowed the demon to enter his mind; this, along with the amount of information he seemed to simply produce on the spot, made Fiddleford increasingly uneasy of the portal and of Ford's mysterious collaborator, as Ford never mentioned Bill's identity to his partner.

On January 18, 1982, Ford and Fiddleford performed their first trial with the active portal, which quickly went awry, as the rope that was attached to the dummy they intended to send through the portal became tangled with Fiddleford, sending him briefly through the portal head-first. Upon his return, an alienated Fiddleford muttered incoherencies before uttering a prediction about "the beast with just one eye." In Gravity Falls: Journal 3, it is revealed that Fiddleford saw Bill removing his exoskeleton to feed. He promptly abandoned the project.

The suspicion planted in him by Fiddleford led to a confrontation between Ford and Bill, during which Ford learned that Bill had tricked him, as the portal was meant to act as a gateway to the Nightmare Realm, allowing the demon to bring chaos and destruction into their universe. Horrified and betrayed, Ford shut down the project and attempted to destroy all knowledge of the portal with help from his brother Stanley Pines, who separated from him because of a false accusation on an accidental act, before accidentally falling through it himself after an argument with Stanley. Guilty, Stanley vowed to find a way to reopen the portal and save Stanford while taking his name and turning his shack into an oddity attraction called the Mystery Shack. Bill either could not see Ford in the thirty years he spent lost in other dimensions, or didn't care to, as Ford would remark that they had not seen each other in many years. With the loss of his human pawn, Bill also lost physical access to the third dimension.

Season 1
Bill's likeness is often seen in the series, as each episode contains 'hidden triangles' and even images of Bill himself, such as in "Fight Fighters", can be seen, as well as his likeness in the end of the intro.

"Dreamscaperers" is the first time Bill is directly addressed and introduced in the series. In an attempt to take over the Mystery Shack once again, Gideon Gleeful summons Bill. Gideon tells him to steal Stan Pines' safe combination directly from his head, so that Gideon can steal the Shack's deed. Bill agrees, but in return, Gideon would have to help him in his own plans, which are not revealed to the viewer. Gideon agrees immediately 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 Soos into looking for the memory of Stan's safe combination first, knowing they'd 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 reads the combination out loud to Gideon (to whom he is connected), Mabel shoots the memory door into another memory of the bottomless pit with a nyarf dart. Gideon breaks off the deal, to Bill's fury. Bill turns his anger toward Mabel and Soos by bringing their 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 mindscape they can do whatever they want. They battle Bill and he is nearly defeated. Just as though it seems he will be forced out of Stan's head, he puts a stop to everything instead. Impressed, he decides to let them go, and after warning them of a mysterious darkness that will change everything they care about, he tells them that he'll be watching them. He leaves in a representation of the zodiac, almost identical to the one that appears in his entry in Journal 2.

Season 2
Bill Cipher appears again in "Sock Opera," when Dipper is trying to figure out the password for the laptop from "Into the Bunker." He offers the laptop's password in return for a favor, but Dipper refuses the offer. Later, at the moment the laptop is on countdown for complete data erasure 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, which 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 activates the pyrotechnics of the play, destroying the puppets and removing any vessel Bill could use to talk to the kids.

In "Northwest Mansion Mystery," he appears on a tapestry hovering over a forest fire with two men either begging for mercy or worshiping him while skeletal corpses are underneath them, foreshadowing bad events.

At the end of "The Stanchurian Candidate," after a prison-bound Gideon fails to get his father elected mayor, he is shown to have drawn Bill Cipher's zodiac on his cell wall and hidden it behind a cat poster. The symbols on the zodiac have been changed around, and some have been altered. Gideon tears down the poster and completes the drawing by drawing Bill's eye before telling it he's ready to make a deal.

In "The Last Mabelcorn," Bill Cipher appears in one of Ford's dreams, telling him that he's been preparing for "the big day," going on to say that Ford can't keep the inter-dimensional rift safe forever. Bill throws a copy of the rift down to the ground, opening a red triangular portal in the sky and setting fire to Ford's mindscape. Ford yells at Bill to leave his mind, telling him he has no dominion in the real world. Bill leaves through the portal, telling Ford that "things change."

Far later in the episode, Bill appears in flashbacks as Ford explains his time spent with the demon to Dipper. In the past, Bill and Ford were partners. Bill could enter Ford's mind at any time, and with his help, Ford built the portal. However, after Fiddleford came out of the portal traumatized by the horrifying things he saw, which were Bill's actual plans, Ford realized Bill had lied to him. He confronted Bill, who revealed his plan to merge the Nightmare Realm he comes from with the real world, causing the apocalypse. Ford broke off his partnership with Bill then and there, despite Bill's warnings that he couldn't stop the rift from happening. Ford shut down the portal and swore never to trust Bill again.

At the end of the episode, Bill watches from the Nightmare Realm as Ford and Dipper manage to create a "Bill-proof" barrier around the Mystery Shack by using moonstones, mercury, and unicorn hair. Undeterred, Bill decides to possess someone outside the shack instead.

Near the end of "Dipper and Mabel vs. the Future," Bill approaches Mabel by possessing Blendin Blandin, recognizing Mabel's wishes of wanting summer to never end because of Dipper's plans to be Stanford's apprentice and therefore never being with her as she expected. Bill (as Blendin) convinces Mabel to give him the inter-dimensional rift, which he says can be used to create a "time bubble" that can make time stop. Mabel gives Bill the rift, which he promptly smashes with his boot. Bill reveals himself and leaves Blendin's body, knocking out Mabel with a snap of his fingers and initiating Weirdmageddon.

In "Weirdmageddon Part 1," after opening the rift, Bill gains a physical form and imprisons Mabel in a bubble. He introduces himself to the people of Gravity Falls, claiming to be their new ruler as well as introducing his friends to the people. The townsfolk refuse to submit, but Preston Northwest welcomes him instead, offering to be one of his "horsemen of the apocalypse." Bill thinks about the offer, but instead decides to 'shuffle the functions of every hole in his face', disfiguring Preston's face, creating fear in the people. He begins "redecorating" the town by unleashing Eye-Bats that petrify and abduct the townspeople, summoning the Fearamid, and sending out bubbles that instill madness and chaos in everything they touch. Bill recreates the opening theme song in the process.

When Bill and his friends prepare to cause havoc, Ford attempts to shoot Bill back into the rift with his quantum destabilizer, but misses because of being thrown off focus by a chaos creature. When Bill notices Ford and Dipper, he blasts the clock tower. Ford, pinned under rubble, begins to tell Dipper that there's another way to defeat Bill. He is cut short when Bill appears, towering over Ford. Bill captures Ford and presents him to his friends, telling them that Weirdmageddon wouldn't be possible without Ford. Bill makes an offer with Ford and tells him it's not too late to join his side. Ford refuses, so Bill turns him into a golden statue to use as a back-scratcher. Dipper, who has gotten back to street-level, yells that he's had enough. Bill flies over to Dipper, asking the boy what he could possibly do to defeat him in one shot. Dipper flips through Journal 3, trying to find Bill's weakness. With no answers, Dipper panics, and leaps towards Bill, trying to punch him. In response, Bill knocks Dipper backwards, causing him to fly into a tree. Bill then telekinetically seizes the three journals, burning them in front of Dipper, with two crippled pages surviving. Bill tells 8 Ball and Teeth that they can eat Dipper for a snack. Bill then converts a random car into a sleek getaway ride for himself and his other friends. The car flies away to the Fearamid leaving Dipper, 8 Ball, and Teeth behind.

Bill and his friends are later seen having a rave party inside the Fearamid. Suddenly, the Time Paradox Avoidance Enforcement Squadron, Blendin Blandin, and the Time Baby barge in, attempting to arrest Bill for possessing Blendin and almost destroying reality. Bill vaporizes the Time Police and Time Baby instantly, and the party resumes. 8 Ball and Teeth approach Bill, informing him they failed to eat Dipper. They ask him if he's worried about Dipper freeing Mabel, but Bill says he's not concerned, and that he has "someone on the case."

In "Weirdmageddon 2: Escape From Reality," Bill has been in power for four consecutive days. Most of the townsfolk have been petrified and stacked into a "massive throne of frozen human agony" for Bill. He announces his plan to take Weirdmageddon worldwide, and the demons make their way toward the edge of Gravity Falls. But instead of escaping to the rest of the world, they hit a strange force field-like energy dome that keeps Bill and his chaos stuck in the town.

Later in the episode, Bill is angered and unable to understand why he and his friends aren't able to extend their reach and leave Gravity Falls to dominate the world. He realizes that Ford is the only one able to understand the shield and contemplates his next move. He is interrupted by Keyhole, who informs him Gideon, Mabel's jailer, has failed to stop Dipper, allowing him and his group to enter Mabel's bubble. Bill is not worried by this, calling Mabel's bubble one of his most diabolical traps yet, as inside is a manifested fantasy world where Mabel can avoid the future after her distraught with Dipper's choice. He asks for Gideon and tells Keyhole to take the day off.

In "Weirdmageddon 3: Take Back The Falls," Bill reverts Ford from his gold state. He explains to Ford that he, along with the rest of his friends, can’t escape Gravity Falls. Ford thinks that this is due to a natural magnetism attracting weirdness to Gravity Falls, the event he’s studied for years, a force so strong that it forms a barrier that prevents that weirdness from going outside the town. He says there’s a way to break this barrier, but he’d never tell Bill. Bill tries to persuade Ford by telling offering him unlimited power in a world without restrictions or laws. Ford again refuses, calling Bill insane. Bill decides to find the equation needed to break the barrier in Ford’s mind. However, Ford reminds Bill he can’t unless he makes a deal with him. Bill decides to try and find Ford’s weakness and force him to make the deal, chaining him up further.

Bill is later seen torturing Ford by blasting him with lasers until he agrees to his deal. Though Ford is in pain, he still refuses to give in. Before Bill can start torturing Ford again, he is interrupted by the Shacktron, a gigantic mech created by Old Man McGucket, with the help of Dipper, Mabel, and various townsfolk. They converted the Mystery Shack into a powerful machine to fight Bill and rescue Ford, who knows Bill's weakness. Bill finds it "adorable" that the refugees are fighting back, and orders his henchmaniacs to fight them. However, his minions are quickly defeated by the Shacktron, and Bill is upset as Ford congratulates Dipper and Mabel for their efforts. Bill realizes Ford cares about the twins, and wonders if torturing them will be more effective than torturing Ford. Bill turns Ford back into a gold statue, and flies over to the Shacktron. He attempts to crush the Shacktron with a giant fist, but it remains intact thanks to the "Bill-proof" barrier surrounding the Mystery Shack. Bill becomes enraged and repeatedly punches the Shacktron. The refugees use the dinosaur attached to the Shacktron's left arm to tear out Bill’s eye and distract him. Realizing now is their chance to rescue Ford, a team composed of the twins, Stan, Soos, McGucket, Wendy, Pacifica, and Sheriff Blubs is ejected out of the Shacktron, using parachutes made out of Mabel's sweaters to land inside the Fearamid.

Everyone lands right next to the human throne, but Dipper is unable to figure out how to unfreeze everyone. Gideon Gleeful, trapped in a cage hanging from the ceiling, explains that Mayor Tyler is the load-bearing statue in the human throne, and if he’s pulled out, the whole throne will fall apart. When Dipper does so, it sets off a chain reaction. As the chair collapses, Gideon’s cage is knocked to the ground and breaks, freeing him. The residents are returned to normal, and Ford unfreezes as well. When Dipper and Mabel ask Ford what Bill’s weakness is, he explains that the way to thwart Bill is by using a zodiac with ten symbols. When each person that correlates with a symbol stands on a drawn version of the zodiac and they hold hands, it can create a force strong enough to vanquish Bill. Meanwhile, Bill is still fighting the Shacktron. It manages to pin Bill to the ground, but Bill realizes its legs aren't inside the unicorn barrier. Bill utilizes this weak spot to flip the Shacktron over, tear off a leg, and smash it into the Shacktron, sending it flying. Back in the Fearamid, the townsfolk that aren't represented in the zodiac run away, leaving only Dipper, Mabel, Soos, Wendy, Gideon, Robbie, Pacifica, McGucket, Ford, and Stan. For a moment, it seems that they will be able to complete the ritual. However, after Ford corrects Stan on his grammar, Stan pushes Ford, breaking the link. The two begin to fight as Mabel and Dipper try to stop them. While they’re distracted, Bill looms above them, having beaten the Shacktron and regenerated his eye.

Bill sends a wave of fire at them, burning the zodiac away. He also traps Stan and Ford, binding them with ropes. The resistance prepares to fight against Bill, but the demon snaps his fingers and turns everyone but the Pines into tapestries showing their screaming faces. Bill then imprisons Dipper and Mabel in a triangular cell. Bill says he’ll spare the twins if Ford lets him into his mind, giving him one last opportunity. The twins yell at Ford not to do it, causing Bill to angrily fly up to them. Mabel quickly takes out her can of spray paint and sprays Bill’s eye, distracting him again and freeing Stan and Ford. While Bill’s distracted, Dipper takes out his size-altering flashlight and enlarges the cell, making it so he and Mabel can walk through. He and Mabel goad Bill into chasing them down a long hallway. As Bill moves to follow them, Stan and Ford try to escape. However, Bill places them inside a larger cell like the one he put the twins in. Bill then changes into a monstrous red and yellow form and chases the kids throughout the Fearamid, threatening to disassemble their molecules. After recapturing the twins, he gives Ford an ultimatum—let him into his mind, or one of the twins will be killed. Ford reluctantly surrenders as Stan objects. Bill removes the cell and ties up Stan. Ford’s only condition to the deal is that he lets his family go. Bill accepts as he shakes hands with Ford. Bill’s physical form turns to stone as his mental form goes inside Ford’s mind.

Bill was happy that he's inside Ford’s mind is "a perfect, calm, orderly void" (a bleak white landscape) with a single wooden door. When Bill opens it, he’s greeted by Stan playing paddleball inside the Mystery Shack. Stan reveals that while the demon was chasing Dipper and Mabel, he and Ford swapped clothes and pretended to be each other so that Bill would enter the wrong mind. In the real world, Ford takes out the Memory Gun, setting it to erase Stan’s memory completely. In the mindscape, Bill tries to call the deal off as the door shuts and the room becomes enveloped in blue fire. Stan explains Bill's going down and to be erased by the Memory Gun, Bill called him an idiot and asked Stan that don't he realized that his mind destroying too. Bill tries to escape and resorts to bargaining with Stan, but Stan doesn’t budge because Bill's powers were erased and Stan tells him that he's real wiseguy but made one fatal mistake and messed with his family. Bill explains that Stan's making a mistake and Bill will give him anything like money, fame, riches, infinite power and his own galaxy until his form heavily glitches out as he speaks backwards messages, and reaches Stan calling for his last word "Stanley!". Stan punches the weakened Bill into nonexistence as his mindscape becomes consumed by fire. Following Bill's defeat, everyone is freed from the tapestries. Outside the Fearamid, Bill’s henchmaniacs are sucked back into the portal, with the bricks of the Fearamid not far behind. The portal itself closes and explodes into a great shockwave, returning the entirety of Gravity Falls back to its own version of normal. The only thing that remains of Weirdmageddon is Bill’s petrified physical form.

After the credits, Bill Cipher’s petrified form is shown in live action, isolated deep in a forest.

Role in the series
Bill's real name is revealed to be Illuminati, and is revealed to be a Mischiever, the true Lovecraftian Outer God, whose goal is to spread interdimensional chaos. Bill had aimed to go to the fifth dimension to escape the bleakness of his own second dimension, but came across the better alternate of the Nightmare Realm, in which he was their dictator. After hundreds of years fighting defense forces against the unnatural and making friends with oddities, he came across Gravity Falls due to it's dimensional anomalies, first dealing with Mr. Lifecraft before his confrontation with Modoc and Stanford. Now he has secretly been resurrecting himself from Stanley's memory of him and aims to return from the outside of Gravity Falls' magic barrier while infusing chaos magic into a Kingdom Hearts Keyhole to begin a plan of multiversal conquest.