- "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.
Bill, and the Eye of Providence he is based on, appear 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...
"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'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 was reading out the combination to Gideon (who 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'll 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's 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.
Inside Out: Crossovers
He is a triangle with a pyramid design, with an eye in the middle. In the theme song it has a hat on, a bow tie, and stick arms and legs, but lacks them in its most cameos.
- He is based off of 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.
- 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 …………" Foreshadowing his appearance in "Dreamscaperers".
- Alex Hirsch has hinted that Bill is more prominent in season 2 of Gravity Falls than he was in season 1.
- The premiere episode of season 2, "Scary-oke," confirms and/or heavily implies that Bill is the show's true main antagonist.
- His voice actor, Alex Hirsch, is the creator of Gravity Falls.
- He shares a few similarities with the Dreamcatcher, a female disembodied head who is the Doom Raider of the Air element from Skylanders: Trap Team.
- Both of them are antagonists.
- Both are formed mostly of a basic shape.
- Both wear a specific type of bow.
- Both formerly existed in a world of dreams only at one point.
- He unofficially appeared as a pop-cultural cameo in an episode of the adult cartoon Rick and Morty.