Stanley Pines and Bill Cipher Similarities
Both are not what they seem at first sight as both are extremely smart liars; scammers and frauds that trick people for their own gain but Stan's got a good heart while Bill is a highly dangerous and deranged sociopath.
Both have a looooooong criminal history, some of their shared crimes are scamming and fraud, destruction of property, pretending to be professionals in the field of medicine- Bill a doctor/surgeon and Stan a dentist-theft as well as animal cruelty in some cases like when Stan committed llamacide or Bill ripping out a deer's teeth.
Both are showmen who use a cane and present the Mystery Shack and the apocalypse in their respective versions of the intros.
Both succesfully tricked the police-Hectorgon used to be a police officer before he joined the gang and Stan hasn't been caught for 30 years
Both commit tax crimes-Tax fraud in Stan's case and Bill got away with his cult not being taxed by the IRSS
Both traumatized people with their body-2 kids at summerween and Fiddleford when he crossed the portal
They used to go to casinos in their youth-in fact that's where Bill found 8 Ball and where Stan met his ex-wife Marilyn
Both like to represent themselves with beefy arms and a six pack
Both name or refer to their hands or their knuckles with nicknames-Slappy and Scratchy in Stan's case and Love and Pain in Bill's case
Both tend to show one eye to people; Bill can shapeshift and have multiple eyes but in his normal form he's a triangle with a singular eye in the middle while Stan uses an eyepatch for his Mystery Man persona.
Both share mannerisms such as using "Eenie, Minie, You", "Tick tock", saying to "buy gold' and calling Ford "Sixer".
Both use "sucker" a lot as an insult- as well as "pal" to refer to people
Both have a hat belonging to a family member aka their fathers.
Both have somewhat dry sense of humour.
Both think Dipper's distress and fear are funny-Stan teasing him and Bill terrorizing him and his worst moments
Both view pain as funny but have limits-Bill likes humans suffering but even he recognizes when things get excessive (like the women being accused of witchcraft) and Stan laughs at Dipper's pain and Robbie's misery and comments its funny seeing a bird attacking Soos
Both are fonder of Mabel, mostly cause she reminds them of themselves with her chaotic and weird personality.
Both watch and secretly like The Duchess Approves
Both secretly write erotica, Stan with his secret The Duchess Approves fanfiction and Bill with the story The Love Triangle
Both had beef with children and older people (Bill with the Mystery Twins and Stan Twins, mostly Ford but loathes Stanley after his defeat at the latter's hands and Stan with Gideon, two kids at Summerween and owners of roadside attractions)
Both had a kid wearing a costume/uniform and dance for entertainment (Dipper and Gideon)
Both refer to themselves as Masters of Something-Master of Fright and Master of the Mind
Both LOVE to scare people; Stan adores Summerween and he tells spooky tales to the costumer in Little Shop Gift of Horrors whereas Bill likes to spook people through different means and/or causing them nightmares-Not to mention both refer themselves as Master and King of Fright
Both have messed with babies-Stan scares one in Summerween and Bill annoys and mocks Time Baby
Both have fears to certain things-Stan fears heights and Bill fears 3D glasses, blinds and TV static.
Both wore a red demon costume at one point
Both use the trick of their skull showing up to scare people
Both are reckless drivers
Both were responsible for putting Gideon behind bars-Stan by revealing the truth about him and Bill by placing him in a tiny cage to dance for all of eternity
Both have dolls of themselves and piñatas of their face
Both once used a giant balloon of themselves to appeal to the masses.
Both are artists (the attractions of the Mystery Shack were all Stan's inventions, Stan was the artistic one between him and Ford, he created a wax museum, he had a comic called Lil Stanley and created the Mystery Shack and Bill created the Fearamid, has a knack for graphic design as shown in his book and draws blue and red triangles in therapy-No to mention both have a scribbly style when it comes to drawing)
Both took a place and modified it to make it their home-The Mystery Shack and Gravity Falls (and the Nightmare Realm but we dont truly have any info on how things were before Bill)
Both tried to hypnotize someone to do their wishes-giving your free will to Bill Cipher and buying keychains from the Mystery Shack.
Both have odd collections-Bill has distorted human heads and Stan just made his in the Shack
Both have a long track of failed attempts to reach their goals-Fortune and Power-but their lives change slightly for the better once they're reached by Ford-Stan's no longer homeless and Bill had his portal.
Both seem to like certain types of animation (Stan likes Stop Motion while Bill likes Rubberhose, referring to those as a riot) and created animated shows/films that failed (one of Stan's failed products was a cartoon called Welcome to Gravity Town-a parody of Gravity Falls-which was unfortunatly cancelled and Bill Cipher Symphonies selled awfully)
Both don't think very highly of McGucket (Bill sees him as a hillbilly and the 3rd wheel to his relationship with Ford and Stan just sees him as the local kook and refers to him as "this guy" or "possum breath")
Both refer to Gideon in similar ways by remarking his height
Both gave Mabel and Ford a limit of three days to do something
Indecent exposure where they took off their shirt.
Both plan to have the person that failed a challenge wear something humiliating for a period of time-A dunce cap for as long as they live and a LOSER shirt for the rest of the summer
Both have quite a few exes; Stan has around 7 ex-wives and had temporary girlfriends like Carla Hotpants McCorkle and Lady Susan and Bill had his fair share of wives as Silas Birchtree and despite saying he doesn't have any exes, its heavily implied he dated a black hole and went out with Bloody Mary and we got the whole situationship he and Ford had going on. And both still miss some; in the game for Nintendo DS Legend of the Gnome Gemulet Stan still misses Carla and Bill clearly misses Ford
Both are the only characters that ever bring up Shermie Pines in conversations
Both refer to things of the USA goverment in inappropiate ways-Stan refers to the Liberty statue as hot and Bill adresses Martha Washington as Hot lips
Both have unhealthy eating habits-Alex mentioning Stan has a beer gut but avoids consuming alcohol and smoking with the kids present and Bill not only introduced Ford to Myclonic Jerk in the karaoke night but also got drunk after the breakup with Ford and its highly possible he's serving alcoholic punch at his parties and the book implies he does drugs.
Both seem to like pasta with Stan eating Dipper's spagetthi and Bill exclaiming you can summon him by giving him a pasta dish in the book
Both are implied to have a past with drugs, Stan with cocaine during his mullet era (and having a beer gut) and Bill is implied he does drugs in the book
Both had their belongings set on fire by an old lady-Ciphertology's quarters were set on fire by Emmaline Butternubbins while Stan's car was burned at least twice by Granny Sweetkin
Both make cannibalism jokes
Both have used different identities across the years for their plans-Stan by adopting fake identities in the 10 years of homelesness where he got kicked out of most states, later using Ford's name for 30 years and tricking Bill by disguising himself as Ford and Bill not only by introducing himself as a goat named Vinegar Pete to women so they could start witchcraft but tricking people around them by possessing Ford and Dipper's body and also by pretending to be Soos and Blendin or persons like a priest or Silas Birchtree.
Both revealed embarrasing info about Dipper to people- Stan shares the incident where he was caught singing Disco Girl in the bathroom or that he's really sweaty to the Agents and Bill shares embarrasing secrets about Dipper to the readers of his book like when he had his fly down during the entirety of Weirdmageddon, the time he clogged the Northwest Mansion's toilet and blamed it on the ghost, the times the Fire department had to be called to get him out of dangerous situations he put himself in, his poor attempts at baseball and his internet search story.
Both gaslighted members of the Pines family about stuff like their true nature and the intentions of their plans like Stan not only about the weirdness of Gravity Falls but also the Portal to rescue Ford whereas Bill also lied about being a divine muse and just wanted to use the portal to wreak havoc across Ford's dimension.
Both were seen as the bad kid growing up for stuff that wasn't really their fault in unwelcoming enviroments-Bill for his genetic mutation and Stan for not having an IQ as high as Ford's.
Both mock Ford's way of talking/sounding
Both wink in ways people cant see (Im winking under the eyepatch and "wait, you cant tell im winking")
Both are mama's boys, having a better relationship with their mom than their dad (Scalene sang him his lullaby 'Rockaby Billy', Scalene's name triggers Bill's anger upon hearing it from time baby, Bill calls her when drunk and asks sadly where did she go, its heavily theorized and somewhat implied his bowtie used to belong to her hence he's carefull with it, readjusting a few times and screaming if it suffers any damage and Carynn saw Stan in a positive light unlike the rest of his family and cared for him, being one of the only two persons that assisted his fake funeral)
Both made a mistake by accident in their youth which makes it impossible to go back home and chaged the course of their life forever-Bill didn't mean to harm anyone but by attempting to show people the stars, he set his home ablaze and he got covered in Euclydian blood and Stan got kicked out of his home by accidently ruining Ford's project which denied him the entrance to the school he wanted to go leading him to scam his way through life to survive.
Both were more than willing to create an apocalypse for their own gain and to bring Ford back.
Both are kinda petty-Bill insults the Pines individually, was gonna kill Mabel for being a nuisance to him in Weirdmageddon Part 3 and still mocks the Shaman after all this time with "In your face, Shaman!" and Stan blames his mullet on Ford and goes out of his way to take revenge on the owners of local roadside attractions as well as telling the kids to get him a bigger tombstone than Ford if he dies
Both downplay the damage they've done to their partners, friends or family-Stan doesn't view his actions towards Carla McCorkle's boyfriend as bad, offers treasure hunting in a really, really bad moment, pins all his mullet era problems on Ford and Bill doesnt think much of invading Stan's mind as to him it was just a job Gideon asked him to do, views the Euclydian massacre as something good to cope with the trauma that left him, sees as hypocritical that hes the bad guy for taking Dipper's body when Mabel did it too in Carpet Diem, refers to the whole situation he had with Ford as melodrama, portraying the abuse and fear he made Ford go through as a harmless joke or non lethal warnings for Ford to stop whining and reactivate the portal and sees both the Shaman and Ford as drama queens for taking extreme measures to prevent his plans
Both of them demand awards when they dont truly deserve them and have stolen prizes
Both of them had issues with certain days or holidays of the year (Stan wanted to erase Soos's birthday off the calendar and heavily disliked both the Pioneer day and the festival approaching the town while Bill clearly has issues with Christmas and got into an argument with the Void for saying she invented a holiday to skip work)
Both of them wanted to destroy one of the journals-Bill actually managing to destroy all 3
Both have a scar that was an indirectly created by Ford in some way (Stan's tattoo was a result of them fighting and it was totally accidental on Ford's part where Bill ends up with a giant scar across his entire body as a result of Stan and Ford's plan where Stan punched him)
Both gave strange bevarages to people like Soos and Ford-The Drippy Stan and Myclonic Jerk.
Both view Ford as their other half, just in different contexts-Bill in a more romantic one and Stan in a brotherly way.
Both are given the cold shoulder by Ford upon seeing eachother again after 30 years.
Both hurt Ford the most and he wants them out of his life-Stanley's actions were at least accidental where Bill's were done with pure intent but although hurt, Stan respect Ford's wishes whereas Bill refuses to and keeps butting in his life. At least Stan earned Ford's forgiveness in the end
Both think of Ford and Dipper as nerds who like homework but have the worst of lucks when it comes to dating. With even both of them referring to Ford by nicknames linked to his intelligence-Pointdexter and know-it-all by Stan and Smart Guy, Brainiac and IQ by Bill
Both mock Ford's interest in D,D&MD by insulting the game or referring to Ford as Mr Tabletop Gaming
Both werent that fond of Mabel's and Ford's pets, at the very least Mabel got to keep hers and its highly theorized that Frilliam came back at one point as we see an Axolotl in Tourist Trapped
Both may not show it initially but are secretly very lonely, seeking company and remorsefull for their past and their mistakes with Bill calling himself a monster and Stan regretting everything he did and said to Ford.
Both became leaders of their respective residence during Weirdmageddon-Stan was the leader of the resistance living in the Shack while Bill ruled as the New Lord and Master of humanity during the apocalypse.
Both aint that great at leadership-Bill could have searched different places across the multiverse to find for him and the Henchmaniacs like how The Oracle did while Stan although having search parties in order to look for supplies and offering aid to whatever survivor they could bring to the Shack, he opted for staying in the Mystery Shack instead of finding other solutions like maybe evacuating the town and also planned to eat the gnomes.
Both went to jail in different occasions (Bill twice by him getting arrested for destroying a bar and later ending up in the Theraprism after Weirdmageddon whereas Stan was at least thrown in jail 3 times)
Both dont respect medical staff
Their advice is constantly lying about things
They talk in similar ways when referring to themselves retorically: What am I, a saint?/ What do I look like, a fortune cookie?
Both seem to like pirates-Stan played that as a kid and liked wearing a black eyepatch (which I now realized he does that currently as well) and Bill refers to himself and the Henchmaniacs as a pirate crew in the book
Both of them bring attention to themselves in parties by clicking utensils against objects they carry like statues or bottles
Both want to pin their crimes on somebody else-Stan's darkest thought is to pin all his crimes on Soos and Crableman has been tricked into taking the fall for Bill's crimes
Both hold no respect for the laws of physics