Who Is Negan?
With his leather jacket and massive frame, Negan is a hulking presence in every panel he appears. This is amplified by his dialog, an unnerving stream of profane politeness that would make the characters on Deadwood blush. He is without a doubt the most worthy — and most terrifying — motherf#@%ing foe Rick and crew have ever faced.
Forget about the Governor. Forget about the cannibals at Terminus. You can even forget about the 1,000-strong horde of zombies currently overwhelming Alexandria. Negan is it.
In the comic, he’s the leader of the Saviors, a group that “protects” surrounding communities from the walker hordes by demanding half of each community’s supplies in exchange. In other words, it’s a classic protection racket, held together by a brutal code of honor established by Negan that punishes disobedience with a visit from his fetishistic companion, a baseball bat wrapped in barbed wire that he affectionately calls Lucille.
Rick crosses paths with Negan after Alexandria comes in contact with the Hilltop, a community under the Saviors’ protection. The resulting power struggle leaves multiple major characters dead and sparks an all-out war between the factions.
Why Are Comic Fans Freaking Out?
Negan is the most compelling character in The Walking Dead universe, and his appearance shakes up the narrative in a way not seen since the original outbreak. He repels you, and yet at the same time you crave to see what he does next, because it’s rarely predictable.
But what really draws you in about Negan is that in retrospect, there’s an internal logic to his behavior — it’s just warped by his outsized id and the knowledge that after the world ends, the one making the rules is the one swinging the biggest, baddest bat. He respects strong-willed people like Rick and Carl even when they’re actively working to destroy him because they conform to his moral code, in the same way he eviscerates a potential double agent because he doesn’t have the “guts” to face his problem head-on.
Oh, and also? He and his men are responsible for the deaths of two major characters who are currently alive on the TV show.
Comic fans have long debated how the showrunners would adapt Negan. His aggressively extreme characteristics seem difficult to bring to non-premium TV — even on the boundary-pushing AMC. Some wondered if Negan’s arc would appear at all, a rumor comic creator Robert Kirkman stoked when he joked that the show’s pacing meant that they’d get to Negan by “somewhere like Season 12.”
Jeffrey Dean Morgan as Negan .
PLEASE KEEP IN MIND THE TV SERIES AND THE COMIC BOOK SERIES HAS A DIFFERENT SCRIPT !!!!!!!!!!!!!!!!!!!!
The Saviors are a large group of antagonistic survivors who were mentioned in "A Larger World" and first appeared in "Something To Fear". The Saviors use a large factory surrounded by a wall of impaled and tied zombies as their base.
The Saviors were, at the beginning, individual survivors. Each member presumably met at the Hilltop Colony. Sometime after the Colony was established, a separate group had formed within the colony, led by a man named Negan, to kill nearby zombies in the area. Judging by their members, the group consisted of the more physically strong and violent members of the Colony.
Soon, Negan's crew had become one of the largest organized survivor groups in the apocalyptic world. They became more and more violent with their ways as they grew in numbers and confidence, and they eventually degraded into committing crimes against other living survivors, which included murder, blackmail, theft, rape, and other various transgressions.
At some point, Negan dubbed his group the Saviors, demanding half of all the rations and supplies from the Hilltop Colony. If the Saviors did not get what they wanted, they gave out deadly messages or severe beatings. In return, the Saviors would kill all zombies surrounding the Hilltop Colony. It is unknown if the Colony had initially resisted the demands, but it is known that they submitted to the Saviors' wishes and followed through with the process for sometime before Rick's group had encountered the Hilltop residents.
The Saviors' main base of operations has shown to be in a heavily fortified factory with a secure fence surrounding it. The only entrance has shown to be surrounded by a horde of chained and impaled undead, supposedly to discourage intruders from attacking, and which forces entries and exits into a small path only big enough for a single vehicle or a few people on-foot without the risk of being eaten by the surrounding undead. Dwight referred to the base as the "Sanctuary". 
The Saviors possessed roughly 70 members before the war, a number of them having taken position around various parts of the wasteland watching each survivor community, including several surrounding the Alexandria Safe-Zone. One particular outpost is located within a few miles walking distance from the Alexandria Safe-Zone, with a female member present, revealing the Saviors have women within their ranks. 
As Rick's group returned to the Alexandria Safe-Zone from the Hilltop Colony, they were confronted by a four-man squad of Saviors, who demanded that they turn over their goods in the name of Negan. As Rick Grimes had never dealt with the Saviors before, he made the decision to oppose their demands and signaled to Andrea to attack. Andrea shot two of the Saviors to their deaths while Michonne leaped out of the van and decapitated another. Rick informed the surviving Savior, who appeared to be the four-man squad's ringleader, to return to Negan with a message: the Saviors no longer need to protect the Hilltop Colony and that, as they demanded the colony, they owed Ricks' group half of their supplies now.
The remaining Savior fled while Rick and the others returned to the Alexandria Safe-Zone. Later, Rick held a meeting and told the residents of the agreement he made with Paul Monroe and Gregory about protecting the colony from the Saviors, referring to them as hot air and a lesser threat, and promised that they would not be much trouble. Rick then asked if anyone disagreed to protect the Hilltop Colony in exchange for food; no one objected and the decision was made. The next day, early in the morning, Abraham Ford and Eugene Porter left for several stores to collect spent bullet casings and tools to make new ammo. Eugene pressed Abraham to make the journey.
However, Eugene was unaware of the Saviors' planned retaliation attack for the deaths of three of their group by the hands of Michonne and Andrea, as Rick had wished to wait until morning to tell them of the new threat. While the two conversed, the topic led to Rosita Espinosa, Abraham's former girlfriend. Abraham told Eugene that he regretted the way he had treated Rosita and left her, and expressed that even though he no longer loved her, that he genuinely hoped Eugene could bring Rosita happiness the way Holly had brought him happiness.
However, Abraham was then abruptly struck with a crossbow arrow through the back of his head and out his eye, effectively killing him. Dwight, a member of the Saviors who fired the arrow, then took a stunned Eugene hostage.
The Saviors used Eugene to lead them to the Alexandria Safe-Zone and demanded that Rick let them in. Rick refused, and a firefight ensued which led to almost a dozen Saviors deaths. Eugene used the commotion to bite Dwight in the crotch and escape death as Dwight and the remaining members retreated. Rick and Andrea chased the Saviors to kill them, but instead of finding any of them, they found Abraham's corpse being gnawed on by a zombie.
After they disposed of the zombie, they brought back Abraham's body for burial in Issue 98. Late in Issue 99, a small group of Saviors spied on the colony with one Savior telling the others to inform Negan that they will attack at dawn.
Rick led a group of Community survivors which included Michonne, Carl, Glenn, Maggie, Sophia, and Hilltop Colony[Hilltop Colony following the death of Abraham. Along the way, they realized they had underestimated the length of time it would take to reach Hilltop, and decided to stop on the roadside for the night. At some point during the night, a group of four Saviors snuck up on their vehicle and captured Rick. His captor ended up being the Savior who Rick had let live earlier in order to deliver a message to Negan. The group of four alerted Negan, along with a bulky group of Saviors in the area, that they had captured Rick.
Negan arrived with his fellow Saviors and proceeded to taunt the group while attempting to mentally break Rick before the others. He proceeded to inform them that they and the Alexandria Safe-Zone were now property of the Saviors. In retribution of the violence towards his men, he told them that one of them would die from his favorite weapon, "Lucille", a baseball bat wrapped with barbed wire.
Before the decision was made of who to kill, Negan threatened to have Carl raped if Rick continued to resist his rule. He also personally threatens to rape Rick before the group as well as point out his discomfort with being considered racist, so he decided to use the "eenie-meenie" method to select his victim, who was eventually revealed to be Glenn.
After Glenn was brutally beaten to death before the others, Rick promised to kill Negan one day. Before leaving, however, Negan beat Rick with his bare hands, telling the group that they were to now answer to the Saviors and that they would be in Alexandria in one week to pick up their "offering". Rick begrudgingly accepted their new rule over the group, only in hopes that it would let them kill Negan and drive off the Saviors in the future, though this was met with anger by the others. To this end, he released their only captive of the attack on the safe-zone, Dwight. However, he prompted Paul to follow behind in hopes that he could find out where it is the Saviors are located.
As Paul carefully followed Dwight back towards the Saviors base, Negan made well on his promise to return to Alexandria for their offering. His Saviors proceeded to interact with the safe-zone while Negan talked with Rick about the lay-out and emasculate him before the group, forcing Rick to give up the majority of Denise's narcotics. As Negan lead his group out of Alexandria, neither he or Rick noticed that Carl had climbed aboard one of his cargo trucks.
Upon Dwight's return to the Saviors base, others had found that he was being followed and captured Paul as a result of this. Having deduced Rick's true intentions, Dwight had Paul brought back to the base only to find he had escaped, thus causing him to "forget" it had ever happened.
The base, once a type of mill or factory, is revealed to be surrounded by a wall of piked zombies, still alive but stuck on poles and spears dug into the ground. Once inside the base, Negan returns as well and the Saviors are shocked to discover that Carl Grimes had in fact stowed away with them. Carl proceeds to kill six saviors using Abraham's automatic rifle, before losing control to it's rapid-burst and running out of ammo. Dwight violently attacks the child, only to be stopped by Negan who has shown further interest in the young child and gives him a small tour of the location.
It is revealed that the Saviors are in fact a cult of sorts, the followers of Negan bowing and chanting to his every word as if he were a Pharaoh in ancient Egypt. The people are divided amongst those closest to Negan, such as guards, henchman and his multiple "wives", as opposed to the common followers who live on a point-system that is intended to replace monetary value in bartering. Carl witnesses to this end, the brutality of Negan's rule as he subjects one of his newer wives' former lover to a ritual punishment, as the wife and lover had reunited in Negan's absence. The man has his face mutilated by a scalding cloth-iron, which Negan presses against his face before pulling away, peeling back the flesh and melted skin which leaves the victim permanently deformed or, "marked with shame".
Sometime after the failed attacks on Alexandria, Negan began personally visiting the Safe-Zone himself along with some of his trusted men. Prior to his arrival though, Negan set up several outposts around the community and positioned scouts outside of their walls before arriving to pick up his demanded supplies.
The members of The Saviors seem to possess great accuracy in their weapon use as they easily were able to shoot the pistols out of the hands of Rick, Holly, Heath, and Nicholas from a distance while taking cover. This is also apparent as a sniper on top of The Sanctuary managed to score two headshot kills, as Rick confronted Negan with his militia, before being killed himself.
All Out War
After Negan manages to escape Alexandria, the Saviors gear up for war against Alexandria and the Hilltop. Their sanctuary is nearly compromised in the attack, as the noise from the battle attracts walkers from around the area and forces them to barricade themselves inside, though Holly is captured in the process. The Saviors and Rick's army engage in several battles, with the Saviors losing outposts and men before they take the fight to Alexandria and inflict severe damage, forcing its inhabitants to retreat to the Hilltop.
Negan instructs the Saviors to begin using infested weapons to ensure their opponents' demises, and they proceed to the endgame at the Hilltop. The two groups fight once more, and during the battle Negan instructs Dwight to hit Rick with an arrow (which he assumes is covered in walker guts), which he does. The Saviors retreat after the militia takes countermeasures against their attacks.
Negan returns to the Hilltop the next day, but his leadership is usurped and Negan incapacitated in a joint effort from Dwight and the militia to end his reign. Negan is handed over to them, and Dwight assumes leadership of the group, effectively ending the war. It is unknown what happened to them after the two-year timeskip.
The Saviors are thriving under Dwight's leadership and are part of the community network. However, it's revealed that at least half of the Saviors are not satisfied with the new policy, and still do not trust Rick.