Buford "Biff" Howard Tannen is the main antagonist of the Back to the Future franchise, with his 1955 self serves as the main antagonist in Back to the Future and the central antagonist in Back to the Future - Part 2, while his 1985 self serves as a supporting antagonist in Back to the Future, a minor antagonist in Back to the Future - Part 2, and the overarching antagonist in Back to the Future - Part 3, his 1985A self serves as the main antagonist of Back to the Future - Part 2, and his 2015 self serves as the overarching antagonist in Back to the Future - Part 2.
Biff was the great-grandson of Buford "Mad Dog" Tannen. He was not very bright and only got through high school by bullying George McFly to do his homework for him. Biff often took pleasure in calling George an "Irish bug", and regularly bullying and tormenting him. He was feared by most of his schoolmates. The only person that he recognized as an authority figure was Mr. Strickland, his high school disciplinary officer. In 1955, he surrounded himself with a gang consisting of Match, Skinhead, and 3-D.
By 1985, Biff's marital status is unknown, although Biff had a grandson Griff by 2015, indicating that Biff had at least one child by 1985. (According to some sources, Biff had a son, Biff Jr., who, it is suggested, owned the Cafe 80's). He may have also had a daughter named Tiff Tannen, short for Tiffany.
Biff was noted for mixed metaphors. For example, he said "make like a tree and get out of here" instead of "make like a tree and leave" on more than one occasion. He also once said "That's about as funny as a screen door on a battleship" instead of submarine. During his theft of the DeLorean in 1991, he said "Have a nice trip, see you next winter!" His insult of choice was "butthead", or — usually when addressing George McFly — (Irish) "bug." One of his routines was to knock on someone's head and say "Hello? Hello? Anybody home?" He liked cars and ended up with a career waxing and cleaning them with his auto detailing business. Biff was still a jerk and more passive-aggressive than a bully, but could be nice when necessary, usually to get out of trouble.
uford Howard Tannen was born in 1936, to Irving Thomas "Kid" and Myra Tannen in Hill Valley, California. Kid and Myra got married on December 6, 1936, simply for the purpose of making it seem like Biff wasn't born out of wedlock. The two parted ways immediately after the wedding, and neither parent wanted Biff. Subsequently, Kid Tannen's mother, Gertrude Tannen, took custody of him. Before he left his son, Kid gave Gertrude a forged birth certificate on March 26, 1937.
In the original timeline, Biff started bullying George McFly when they were kids and never stopped. On their first encounter at high school in 1954, George had a hero sandwich rubbed into his face by Biff after Dale Carnegie's claim in his book How to Win Friends and Influence People that a man cannot remain hostile if one showed one was sincerely interested in him proved somewhat ineffective. On his 21st birthday, Biff spent most of his money betting in horse racing; but lost all of it.
By 1985, Biff would continue to bully and intimidate George, and they both ended up working for the same company, where Biff became George's supervisor (due to George doing all Biff's work for him to get promoted). Because Biff was too lazy or stupid, or both, to do his own reports, he forced George to do them instead. Biff's crush on Lorraine never died either, even after she had married George. On the night of October 25, Biff had convinced George for him to drive his car after work. While driving in an interstate; wrecked the car while drinking and driving has been drinking and driving (at the same time!). Biff was complaining that George had not told him the car had a "blind spot" (though most cars have a blind spot). Biff demands to know who is going to pay his dry-cleaning bill, as he spilled beer down his suit in the crash, then bullies George into writing his reports for work while making a rude comment by calling Marty "butthead".
History was changed when the McFlys' youngest son Marty McFly accidentally traveled back through time to 1955 using his friend Dr. Emmett Brown's DeLorean time machine, interfering with his parents' first meeting.
Marty, using the anachronistic name "Calvin Klein," also managed to get on the wrong side of Biff by standing up to him, something which Biff was not used to. Marty was also indirectly responsible for causing Biff to crash his car into a manure truck, an incident that caused $300 in damage to his car. Seeking revenge, he found Marty and Lorraine in Doc Brown's car on the night of the school dance (November 12, 1955).
Biff's gang trapped Marty in the trunk of another car and Biff tried to get his way with Lorraine. George came along, as part of the plan he and Marty had plotted where George would find Marty "parking" with Lorraine and come to her rescue, but soon realized that the pretend rescue was now a real one. For the first time, George stood up to Biff to stop him from sexually assaulting Lorraine.
Biff responded by twisting George's arm, threatening to break it. Lorraine, trying to pull Biff away from George, was knocked to the ground. George, now enraged, suddenly broke free of Biff's grip and knocked him out with one punch. As a result, George became much more confident, and was no longer one of Biff's victims. Lorraine and George fell in love, and went on to marry.
It is unclear whether Biff found someone else to bully or whether being knocked out by the supposed weakest kid in school had ended Biff's days of bullying people and also instilled at least a rudimentary notion of humility in him.
Since Biff no longer had George to do his work for him, he now had to do things for himself. He started up his auto-detailing business, which he owned and ran himself, and by 1985, the McFlys were among his most loyal customers, and Biff's subservient attitude was demonstrated by his addressing George as "Mr. McFly".
George seemed amused at Biff's efforts to get away with as little work as possible (although Biff's comment about already doing two coats of wax on the car may have been a personal good-natured joke between him and George) though he and Lorraine privately credited him with unwittingly helping them get together. George and Biff appeared to have become friends, or were at least on amicable terms. Biff seemed to be genuinely excited when George's published novel was delivered, suggesting that he at least was happy for his old victim.
At the age of 78, Biff seemed to return to his grouchy and mean demeanor, and was still waxing cars in 2015 (although he had a better grasp of mixed metaphors than he did 60 years before). The fact that he still owned and managed Biff's Auto Detailing may suggest that he has fallen upon hard times and still needs to keep working in order to earn a living. However, it may have also been the case that he was working more as a way to keep active (which some retirees make a practice of). It is clear that Biff is quite bitter and resentful as a senior citizen.
Formerly the bully, Biff was himself being bullied by his grandson Griff. This family relationship was at best a strained one, as grandson and grandfather seemingly did not get along. When Griff and his gang were arrested by the police for vandalizing the Courthouse Mall, Biff said to himself "Buttheads" — likely feeling that Griff got what he deserved.
Biff still seemed to like harassing people, including Marty (whom he thought was Marty's future son), and the handle on his cane was in the shape of a closed fist, which he used to rap people on the head because his own hands were now too feeble to hit anyone hard — although he remained cautious and apprehensive around George McFly. Biff's crush on Lorraine still lingered, as he told the young man, "Say hello to your grandma for me."
Despite Biff's anger at himself for letting life pass him by, he had become a calmer and more astute individual than he had been in his youth; this would lead to problems for Marty and Doc. When he sees what he believes to be Marty's son Marty McFly, Jr., he picks on him for having a failed father. He however, is unaware that the kid he is picking on is actually Marty from 1985, who has traveled 30 years into the future with Doc in the latter's Time Machine, while Marty himself is confused by Biff's insinuation. While Griff and his gang are chasing Marty on their hoverboards, Biff remarks that there is something familiar about this, as this is similar to Biff and his gang chasing Marty 60 years ago.
When he sees the DeLorean, he says to himself he saw a flying DeLorean 30 years ago. Shortly after, Marty Jr. runs out of the café and accidentally bumps into Biff, making the latter confused, as he is seeing "two" Marty McFly Juniors. Sneaking into an alleyway, Biff eavesdrops on Doc reprimanding Marty for abusing time travel to get rich. After Doc disposes the Grays Sports Almanac in the trash, Biff claimed it for himself and remarked that Doc built a time machine. It is possible that he also realized that the kid he just picked on was Marty from 1985, also figuring out more proof when Marty from 1985 said "I did?" when he talked about adult 2015 Marty. He hired a taxi to go to the Hilldale neighborhood, then stole the DeLorean and took it back to November 12, 1955, so that he could alter his life by handing the almanac to his younger self.
Encountering his younger self, he passes himself as a distant relative, the two briefly argue and he reprimands his younger self for getting his mixed metaphors wrong, before transitioning to the Sports Almanac. He gives his younger self the sports almanac so he could become rich. While young Biff initially does not take it seriously, old Biff proves its validity by correctly predicting the score of a college football game, which sparks the interest of young Biff. Old Biff tells him to bet on the winner and he'll never lose. Young Biff says he'd take a look and throws it in the back of his car, only to be reprimanded by old Biff, who tells him never to leave the book lying around. He then tells him to get a safe and lock it up. He puts the almanac in his back pocket, and tells him to lock it in a safe and never tell anyone. He also tells him that sometime in future, some guy claiming he's a scientist will come asking for the book, and when he does, young Biff should kill him. After this, old Biff presumably travels back to 2015.
Just before Marty and Doc returned with Jennifer, Biff returned to 2015 and got out of the DeLorean with difficulty, then suddenly clutched his chest in pain (apparently suffering a heart attack), causing the top of his cane to break off and fall inside the car. He staggered away and slumped behind a parked car; he then fell sideways to the ground behind the car and faded away because of his having changed history. By altering the timeline, old Biff created a new timeline, where he was no longer alive by October 21, 2015. In Biff's alternate reality, it appears he was shot by Lorraine (possibly as revenge for killing George or simply being fed up with Biff’s abuse) sometime in the mid 1990s - presumably with the same gun that killed George twenty-three years before.
In 1985A, Doc discovered the top of Biff's cane and the receipt for the sports almanac in the DeLorean, from which he deduced Biff's theft of the time machine.
Although struggling to see the resemblance between he and his older self, and initially unwilling to believe the old man, over time, Biff came to believe the almanac's validity, though losing the dust jacket cover as it was on his Oh LaLa magazine that Stanford S. Strickland took. Eventually young Biff used the sports almanac to bet on the results of sporting events, since he knew the outcomes in advance, giving him the ability to cheat. In 1958, he placed his first bet on his 21st birthday, which led to him winning his first $1,000,000 and becoming rich. From then on, Biff would continue to get rich by betting on the sports result with the almanac. Biff soon became very rich and powerful, eventually starting up his toxic waste company BiffCo and a casino hotel in Hill Valley (at least twenty-seven stories high), named "Biff's Pleasure Paradise", changing the laws of California to legalize casino gambling in 1979. Biff had apparently used his money to influence American politics as well as California politics.
In addition to his lobbying of legalization of gambling before the California Legislature Biff also spearheaded a constitutional amendment to repeal the 22nd Amendment to the U.S. Constitution. Biff was apparently an admirer of Richard Nixon, whom by repealing presidential term limits, he had helped get elected to at least four terms as President of the United States. Biff had presumably altered the timeline by either bribing to cover up the Watergate investigations or resorting to outright murder. President Nixon had plans (at least as of 1983 while seeking a fifth consecutive term), and leaving the Vietnam War unresolved as of 1983, which meant Biff's ways has affected the entire world as well. Though he was promoted (at least by himself) as "America's greatest living folk hero", Hill Valley in 1985A had become a center of crime, corruption, prostitution and gang warfare — which was not surprising really, since Biff also had control over the Hill Valley Police Department.
Despite Biff's great wealth and many female admirers, Biff did not have the woman he always wanted, and would still have to wait decades before his time had come. In this version of history, he had been married three times. Not much is known about Biff's earlier marriages. Biff's first wife was Marilyn Monroe. That marriage had been dissolved by divorce. Biff's second wife was Jayne Mansfield, who divorced him after she saw photos of Lorraine Baines McFly. The divorce from Mansfield renewed Biff's feelings for Lorraine. On March 15, 1973, Biff shot and murdered George, though Lorraine had not yet learned the truth by 1985A. Biff married her later that year, giving her financial support and offering to help the widowed Lorraine through her tragedy, but he apparently did not adopt her three young children as his own. Biff's power and wealth had gone up to his head, and he was very abusive towards Lorraine. He also paid doctors to drastically increase Lorraine's bustline, and gave only marginal support to his three stepchildren. He may have used his power to keep Dave McFly (Lorraine's 'idiot son') out of jail, but had no qualms about using his power to revoke Dave's probation, presumably by bribing the probation officer. Biff may have also been allowing Linda McFly to live the carefree life of a playgirl, but threatened that he would stop paying off her credit card bills. Biff paid for Marty's tuition at a boarding school in Switzerland, but this may be more likely he wanted at least one of his stepchildren away from him as far as possible since Marty was still a high school student, more so than trying to get Marty the best education he could provide. He carefully kept and preserved the Almanac, the source of his success in his personal safe behind his portrait for further use in the next few years until the Almanac information expired in 2000.
In 1986, Biff's long reign of terror finally came to an end when, in an attempt to visit 1996 in order to obtain future information to help him become President of the United States in 1988, he was instead temporarily sent back by Doc Brown to 1884, where he was murdered by his great-grandfather Buford Tannen upon calling him "Mad Dog." There is also a speculation that he was shot by Lorraine in the mid 1990s. While it is unclear when exactly and how Biff died, it is clear that he did die at some point prior to 2015 after old Biff altered the timeline. Because he was no longer alive by 2015 after having altered the timeline, Old Biff collapsed and faded from existence upon returning the DeLorean after his trip to 1955.
This version of reality was erased when Marty and Doc went back to 1955 and got the almanac from Biff before he could use it, while causing Biff to crash into the very same manure truck a second time. When Marty burned the retrieved almanac and burned it, the timeline returned to how it was at the end of the first film, where Biff was running his auto detailing business.
Once Marty had returned to 1985 for the second time, Biff was spending a second day working as an auto-detailer - but now, he has a red jacket, not a green one.
While normally maintaining an appearance of being obsequious, Biff's original bad attitude still lurked beneath the surface and emerges occasionally, like his reaction to seeing the DeLorean take off and when he snapped at Marty when Marty approached his truck after his adventure in 1885. To be fair, he did think Marty, still in his "Clint Eastwood" disguise, was some punk trying to steal the truck and once he realized who the "punk" was, Biff immediately apologized, once again readily showing his good-hearted behavior.