How are each of The Walking Dead's main villains defeated, and how does the TV series deviate from Robert Kirkman's original comic books? In general terms, AMC's live-action adaptation of The Walking Dead has been a faithful retelling of the source material, featuring predominantly the same crop of characters and following the overall journey from prison to Alexandria to the Commonwealth, albeit with many diversions along the way. Recent seasons have introduced more seismic changes, with the death of Carl Grimes, and his father Rick being whisked away by helicopter towards Hollywood.
Almost every major comic book beat finds its way onto screen in some form or another. The infamous "just look at the flowers" scene was influenced by the comic story of Billy and Ben, and Negan swinging for the fences with Glenn was ripped straight from Kirkman's printed tale. But The Walking Dead on TV often presents these moments with a twist, whether that be substituting Billy and Ben for Lizzie and Mika, or adding Abraham to Negan's list of batting targets. This ensures comic readers aren't entirely clued-up on events to come, but also helps retain a certain level of authenticity.
The same is true when it comes to the deaths and defeats of The Walking Dead's major villains. Usually, the big bads of the zombie apocalypse bow out in a way that mirrors their comic book demise, but with a fresh element that changes the complexion of the death entirely. Here's what each villain's death scene changed.
Shane
Shane's death is a pivotal moment in both versions of The Walking Dead, marking Rick's ascension to undisputed leader and the loss of Carl's innocence forever. Shane's downward spiral is also almost identical between the comic books and TV series. Fresh from an affair with Rick's wife, Shane becomes jealous that Rick has slid back into their lives as if nothing ever happened. Shane feels he would be a better leader for the group and would do a much better job of protecting Lori and Carl, so he plans to get rid of his Rick problem once and for all.
This is where The Walking Dead TV series flips the script. On screen, Rick pretends to surrender to Shane before slyly stabbing him. Carl then arrives to put down the reanimated corpse of his father's old friend. The Walking Dead comics do exactly the opposite, with Carl arriving to find Shane on the verge of killing Rick, forcing the youngster to shoot a still-alive Shane. Rick then returns at a later point and lays to rest his zombified friend. Both interpretations achieve the same result, but perhaps having a pre-teen Carl shoot a main character in the neck was a little too rich for AMC's blood in the early days.
Tomas/Dexter
When Rick's band of survivors set up shop in an abandoned prison, they were forced to assimilate with the locals. Inevitably, not all of the cellmates were friendly, and both versions of The Walking Dead create a sense of mystery around which prisoner could be a threat. In live-action, Rick and Daryl quickly identify Tomas as the potential loose cannon and, sure enough, the criminal begins to intentionally endanger the prison's new residents. Rick responds by driving a machete into the man's skull. The entire Tomas story takes place within only a single episode of The Walking Dead's third season.
Tomas is a composite of two comic characters: Thomas the serial killer and Dexter, the latter of which acted as a more prominent antagonist. Like Tomas, Dexter is distrustful of Rick's group and wants to forcibly remove them from the prison. Also like his television counterpart, Dexter endangers Rick's life while the prison residents are clearing out a crowd of undead, and this decision directly leads to his death. In a much more subtle manner than the machete blow, Rick discreetly shoots Dexter while battling against zombies.
Martinez
Caesar Martinez was one of The Governor's most trusted lieutenants and played a key role in Woodbury's assault on the prison, even firing on Rick's camp with a grenade launcher. Martinez committed a series of nasty and villainous acts throughout The Walking Dead season 3, but drew the line when The Governor began gunning down his own people. Martinez manages to find a measure of redemption by starting his own community away from The Governor, but once big bad Phil comes back into the picture, Martinez is killed by his former leader, knocked into a pit of walkers.
Martinez's comic arc is quite different but covers similar themes. After entering the prison as an ally, Martinez escapes to report his intel back to The Governor. Rick notices and drives after the infiltrator, quickly knocking him to the ground. As Rick approaches, Martinez reveals that he hated The Governor too and that he only intended to bring good people back to the prison, but Rick duly strangles him to death anyway. Although they go out very differently, both versions of Martinez were killed after trying to break away from Woodbury, and both deaths indirectly led to The Governor attacking the prison a second time
The Governor
The first true arch nemesis of Rick Grimes on The Walking Dead, The Governor's comic and TV deaths are almost exactly the same. Compared to the original, David Morrissey's Governor is more outwardly charming and manipulative than the aggressive figure who lopped off Rick's hand in the comic books, and the TV series also delves deeper into The Governor's psyche via a side-story where The Governor tries to redeem himself and ultimately comes back angrier and more evil than ever. Both routes lead to one more fateful attack on Rick Grimes' prison, and it's here that The Governor always meets his demise.
In the comics, The Governor orders one of his Woodbury soldiers, Lilly, to shoot at Rick's family as they run from the fallen prison. Upon doing so, Lilly realizes that she not only shot Lori, but also killed the couple's baby, Judith, who was in her mother's arms. Appalled, Lilly shoots her boss in the head and assumes command of the remaining Woodbury residents. On TV, Lilly is introduced as Tara's sister, who The Governor begins a romantic relationship with after the fall of Woodbury. Lilly is against attacking the prison, and her daughter Meghan is bitten while the others are off fighting Rick. Making her way to the site of battle, Lilly watches as her lover beheads Hershel and then callously shoots the deceased Meghan in the head, finally seeing The Governor for who he really is. Lilly delivers the fatal shot after Michonne had already pierced Philip Blake's chest with her sword.
Terminus/The Hunters
The Walking Dead's cannibal Hunters were stop-gap villains in the comic books, but the Terminus arc lasted considerably longer on TV. After abandoning the prison in The Walking Dead season 4, each of the protagonists are lured to Terminus, a supposed haven at the end of a (very) long railroad track. Happily, Rick's group do unite at Terminus; much less happily, they also find their new hosts to be cannibals. With help from Carol, the heroes manage to escape, shooting up the Termites on their way out, but a select few survive and are led by Gareth in pursuit. The cannibals finally catch up to their prey at Gabriel's church, where Rick and his people slaughter them mercilessly.
In comic form, The Walking Dead essentially presents a truncated version of this story. The Hunters already dwell in the wild, rather than their own community and begin eating Dale (as opposed to Bob). This results in a showdown between Rick's group and the cannibals, with the former quickly seizing an advantage and brutally hacking their opponents to death. This confrontation takes place in the woods, rather than Gabriel's church.
Pete
When Rick's people arrive in Alexandria, they encounter the same teething problem faced previously in the prison - one bad apple who wants to go back to how things were before Rick came along. In Alexandria, this enemy is Jessie's abusive husband, Pete. Rick takes exception to Pete almost immediately in both the comic and the TV series, and the antagonist becomes increasingly erratic in his hatred, eventually plotting to kill Rick in front of the entire town. Both versions of Pete die in very similar ways; the villain tries to kill Rick, ends up taking someone else's life, and Rick is swiftly ordered to execute the murderer. However, the details change between mediums. On TV, Pete accidentally kills Reg Monroe with Michonne's stolen sword, then Reg's wife Deanna sentences Pete to death. In the comics, Pete uses a kitchen knife and kills Regina Monroe (a TV gender-flip), again by accident, and Douglas (Deanna's own gender-flip) orders Rick to put the culprit down.
Alpha
As the leader of the Whisperers, Alpha has played a major role in both the Walking Dead comic and its TV counterpart, with Samantha Morton's character arguably even better than the original. Both iterations of Alpha are in the midst of waging war against Alexandria and Hilltop when Negan asks to join their ranks, sprung from prison and supposedly looking for revenge against his captors. After some quality time with the Whisperers, Negan reveals his true intention is to kill Alpha and prove himself as a reformed citizen who deserves to be released from jail.
In Kirkman's telling of the story, Negan worms his way into Alpha's ranks, earns her trust and then cuts her throat in a surprise attack once the pair are alone, before presenting her zombified head to Rick as a trophy and a symbol of his loyalty. All this occurs in the AMC series also, but in the form of a remix rather than a verbatim cover version. Instead of being let out by a disgruntled Alexandrian (Jeffrey Dean Morgan's Negan actually returned to his cell after this), Negan was working under orders from Carol, who had proposed the idea of killing Alpha to Negan as a way Negan could win favor among the community.
The Walking Dead season 10 is currently on hiatus.