Bill Cipher

"Remember! Reality is an illusion, the universe is a hologram, buy gold, BYE!"

- Bill Cipher's most famous quote.

Bill Cipher is the main antagonist of the Disney XD series, Gravity Falls. He is an immensly powerful dream demon from the 2nd dimension who means to bring about the end of the world by opening a rift between his Nightmare Realm and the real world. He also has mysterious motives and a vendetta against the Pines Family, specifically Stanford. He has been running amok in Gravity Falls, Oregon since being summoned by Stanford Pines over thirty years ago. He is also known for his mysterious demeanor and sadistic humor.

He was voiced by the series' creator, Alex Hirsch.

Appearance
Bill is a floating yellow triangle with a single cartoon eye in the center (though sometimes near the upper corner; also known as the Eye of Providence) a black bow tie and a top hat, and thin black limbs. He is sometimes seen holding a yellow or black cane as well. Bill's body also flashes when he speaks, as he has no mouth. However, when angered, his color is inverted, with his eye turning black, outline turning white and yellow turning a glowing red, although his form can change to that which is desired at will. A tapestry hanging from the wall in Northwest Mansion Mystery depicts him as black or ash gray instead of yellow and with a red eye. In The Last Mabelcorn, he appears for a few moments as black with a yellow eye.

In the three-part series finale, Weirdmageddon, Bill assumes multiple three-dimensional forms, including a black multi-tiered and multi-armed pyramid, a three-dimensional version of his default yellow form (including a giant version), and his most horrifying and terrible form of all, that of a colossal red multi-tiered pyramid with eight different glowing limbs resembling a spider, sharp teeth and tongues erupting from his body, and a black eye with a lizard-like yellow pupil, which he assumes during the final battle as he hunts down Dipper and Mabel Pines.

As he is being erased and speaking his hidden resurrection spell, he transforms into several different forms in an attempt to escape, including his angry red form, a stone like form with two stone pyramids which could rotate with one eye one each side which could rotate and a stone block having his arms and bowtie, a distorted form with several green eyes and limbs, flashing between yellow, pink, blue, and orange, before finally assuming his black form with a red eye as seen on the tapestry. When Stanley punches him, he briefly flashes back to his default yellow form before being wiped out completely.

While possessing a person, that person's body will take on a pale tone to their skin, and their eyes will appear yellow with black slits, similar to his own.

If necessary, both Bill's yellow main portion and eye can portray images similarly to a television screen, all of which are seemingly what he is thinking about at the time.

Personality
Bill at first seems to be very benevolent, charming, affable, and polite, albeit obnoxious and slightly sadistic, but this easily changes within minutes of his debut, especially when he reveals his true nature: that of a highly intelligent, manipulative, traitorous and evil psychopath. He usually speaks with a high-pitched voice with a synthesized effect, but when furious or expressive, it becomes deep and inarticulate similar to traditional demon depictions.

Bill seems to display symptoms of antisocial personality disorder. Symptoms include lying, feeling no remorse, and showing hostility and sadism. A bit of a running gag is whenever somebody calls him insane, Bill will proudly agree with them.

He is also very masochistic, as he enjoys hurting himself, as he tortures Dipper's body while possessing it, and has no problem killing or hurting children like Dipper and Mabel. An expert manipulator and master liar, he is clearly capable of fooling others into trusting him long enough for him to betray them in a heartbeat, and is falsely affable enough to influence others into playing pawns or making deals with him (which he will almost always double-cross to his advantage). However, while an easily angered madman, he is also highly authoritative, perspicacious, influential, and decisive, knowing when to pull out of a fight. As of The Last Mabelcorn, Bill is shown to be far more than simply a treacherous and oppressive psychopath; he is extremely calculating, sarcastic and diabolical, easily becoming one of the most fearsome and powerful Disney villains thus far.

Bill is also known for his complete disregard of rules and morals, as he considers laws and physics to be quite senseless and he doesn't even care about the consequences of his actions that can endanger the fabric of existence, as he considers the idea of destroying the Earth as a mere game to him. He dedicated his own existence of spreading complete chaos and his selfish philosophy of doing whatever he wants without care for consequences.

However, in his final moments, Bill is shown to be absolutely terrified of dying as seen when being exploited by his own weakness.

Powers and Abilities
While Bill is vastly powerful and competent, he cannot normally interact with the physical world while trapped inside the Nightmare Realm. He is able to observe the world, but not influence it, as he can only appear to people in dreams, being virtually omnipotent within the dreamscape. Bill can also act by making a pact with a willing vessel, but in doing this he is subject to all the constraints of the vessel body and cannot use his own power to reshape the world at will.

When Bill Cipher escapes the Nightmare Realm, he becomes able to use his full power within the real world, and his power seems to be almost limitless, possibly next to godlike. He is able to reshape reality and everything in it to his will and can even defeat similarly powerful entities such as Time Baby. On the brink of defeat, he offered Stanley Pines "his own galaxy", implying that his power could potentially be on a cosmic scale. However, he has some weaknesses. Namely, he cannot escape the weirdness-attracting bubble around Gravity Falls on his own and lack the knowledge how to undo the bubble, and he is unable to use his powers directly on objects that are protected by a barrier of unicorn hair. Also, he cannot possess someone as long as the host refuse to shake his hand. In the mindscape, Bill is nothing less a thought which means if Bill was in someone's mind that about to be erased, Bill will be erased along with it competently annihilating him from existence.

Quotes
"Oh, oh, Gravity Falls, it is good to be back! Name's Bill Cipher, and I take it you're some kind of living ventriloquist dummy? [laughs] Just kidding, I know who you are, Gideon! (Gideon: W-what are you? H-how do you know my name?) Oh, I know lots of things! (*voice changes*) Lots of things..."

- Bill Cipher after he is summoned

"Ah, Stan's family, we meet at last. Question Mark, Shooting Star, Pine Tree, I had a hunch I might bump into you!"

- Bill Cipher meets Dipper, Mabel and Soos

"You're out of your league, kids. Turn around now before you see something you might regret."

- Bill Cipher

"Boy, you kids sure are gullible! I knew you'd lead me straight to the code! It's funny how dumb you are!"

- Bill Cipher

"YOU! You can't even imagine what you just cost me! Do you have any idea what I'm like (voices changes to a low, demonic tone) WHEN I'M MAD??!!"

- Bill Cipher's villainous breakdown.

"I'm been impressed with you guys. You're more clever than you look. Especially the fat one. (Soos: (to Mabel) He's talking about you.) So I'm gonna let you kids off the hook. You might come in handy later. BUT KNOW THIS: A darkness approaches. A day will come in the future where everything you care about will change...until then I'll be watching you! I'll be watching you..."

- Bill Cipher foreshadowing Weirdmageddon

"Well well well! You're awfully persistent, Pine Tree! Hats off to you!"

- Bill Cipher to Dipper

"Did you miss me? Admit it, you missed me!"

- Bill Cipher

"(Dipper: So which puppet are you going to pick?) Hmm, let's see... eenie... meanie.. miney... YOU!"

- Bill Cipher takes Dipper's body

"(Dipper: I'm gonna stop you!) But how can you stop me... if you don't exist? AHAHAHAHAHAHA!!!"

- Bill Cipher to Dipper

"(Ford: You lied to me! Where does that portal really lead?) Ho ho-looks like Mr. Brainiac finally got smart! Let's just say that when that portal finishes charging up, your dimension is gonna learn how to PARTY! Right, guys?!"

- Bill revealing his true colors to Ford.

"At last! At long, long last! The gate between worlds has opened! The event one billion years prophesied has come to pass! The day has come! THE WORLD IS FINALLY MINE!"

- Bill Cipher

"Alright, listen up, you one-lifespan, three-dimensional, five-sense skin puppets! For one trillion years I've been trapped in my own decaying dimension, waiting for a new universe to call my own. Name's Bill! But you can call me your new lord and master for all of eternity!"

- Bill Cipher to Gravity Falls as Weirdmageddon begins.

"It's time we do a little redecorating. I could really use a castle of some kind! (Bill's castle rises) And how about some bubbles of pure madness?!? This party never stops! Time is dead and meaning has no meaning! Existence is upside down and I reign supreme! Welcome, one and all, to Weirdmageddon!"

- Bill Cipher brings forth Weirdmageddon.

"We'll meet again. Don't know where. Don't when. Oh, I know we'll meet again, some sunny day."

- Bill Cipher singing

"Flat minds in a flat world with flat dreams."

- Bill Cipher describing his home dimension

"So the mortals are trying to fight back, huh. Adorable!"

- Bill Cipher

"(Ford: Bravo, Dipper and Mabel!) Well, would you look at that. Those kids really care about you, and you care about them...(*Voice turns deep*) DON'T YOU?! (Ford: What are you.... Oh. Oh no.) Perhaps torturing those kids will make you TALK!!"

- Bill planning to torture both Dipper and Mabel to coerce Ford into helping him

"All right, Ford, time's up! I've got the kids. I think I'm gonna kill one of them now just for the HECK of it!! EENIE... MEENIE... MINEEE... YOU!!!!"

- Bill about to kill Dipper and Mabel with a snap of his fingers

"(Stan: Hey, look at me. Turn around and look at me, you one-eyed demon! You're a real wise-guy, you know, but you made one fatal mistake: you messed with my family.) You're making a mistake!! I'll give you anything: money, fame, riches, infinite power, your own galaxy, PLEASE! (starts to glitch) NO!! What's HAPPENING TO ME?!!! (reversed) A.X.O.L.O.T.L., MY TIME HAS COME TO BURN, I INVOKE THE ANCIENT POWER THAT I MAY RETURN! (normally) STANLEY!!!!!"

- Bill's last words right before being destroyed by Stanley.

Trivia

 * Bill Cipher's line, "A.X.O.L.O.T.L., MY TIME HAS COME TO BURN, I INVOKE THE ANCIENT POWER THAT I MAY RETURN!", is reversed. He may have said it that way because he does not want Stanley (or anyone, for that matter) to be aware that he could come back.
 * His full name is likely a reference to the Beale ciphers; encrypted manuscripts which are said to lead to a great, hidden treasure and which only one of three have been decoded.
 * This is entirely possible as codes and ciphers are hidden all throughout the series.
 * Bill can be summoned if one were to recite an incantation found in Journal 2.
 * He is based on The Eye of Providence (a common symbol allegedly used by the New World Order), as creator Alex Hirsh confirmed in the Special "Behind the Pines" stating: "What if I took the triangle off the back of the dollar bill, dress him up in a top hat, and stupid little arms and legs, and named him Bill after the dollar?"
 * However, it is currently unknown why he was based on the Eye of Providence.
 * This is also mentioned in one of the journals, where the author has scribbled a note, saying, "He's in my wallet!", and sketched the seal from a dollar bill.
 * Various things were discovered about Bill Cipher during a Reddit AMA, including the possibility of him once having a family, having something to do with Gompers in the past, and his favorite music being 10 hours of Rising Shepard Tone.
 * The AMA also revealed that Bill Cipher thinks in capital letters.
 * It is never made clear what Bill truly is. While he is called a "demon" by other characters, creator Alex Hirsch has confirmed that this is just a name for lack of better description. Ford even states that no one knows really what he is. Because of his reality warping abilities and bizarre nature, it is likely that he is inspired by the Outer Gods of Lovecraftian lore.
 * In addition to being inspired by Lovecraftian Lore, Bill Cipher is somewhat similar to the Lovecraftian character, Yog-Sothoth. This is because both of them are Omniscient and All-Seeing.
 * Bill Cipher is, arguably, the most evil Disney villain, above even Scar from The Lion King and Frollo  from The Hunchback of Notre-Dame. This is due to his goals to rule all of extistence via Weirdmageddon, which is far larger than any other Disney villain's goals. He is also willing to kill children and sees the end of the world as nothing but a game.
 * As Gravity Falls is set to return in a graphic novel series, it can be assumed that Bill may return as well due to the curse he invoked during his last moments.