[SPOILERS: Seriously, don't read if you're not caught up on the show or the comic.]

"The Walking Dead" is set to kick off the second half of its sixth season this month. The biggest twist to this ongoing saga of survival is that a major new villain will soon make his debut: Negan. Jeffrey Dean Morgan plays the Big Bad, a charismatic psychopath who speaks loudly and carries a big stick -- a guy who makes the zombies Rick and friends have faced seem like a golden age.

Fans of the "Walking Dead" comic know Negan well by now, as he's been at the forefront of the series for several years. But for those who only watch the TV version, here are five important things to know about the guy before he makes his live-action debut.

[WARNING: Again, there be spoilers here! Turn back now. Still here? Okay, but you've been warned.]

1. He's Not a Very Nice Guy

Negan is easily one of the most violent and sadistic characters in the world of "The Walking Dead."

He'll murder innocent bystanders without a second thought and smile the entire time. He rarely seems able to speak more than a few words without throwing in an F-bomb (which AMC's censors just love). Some villains are conflicted about doing bad things to good people. Negan relishes the opportunity. The only thing this remorseless killer seems to care about is his trusty barbed wire-coated baseball bat, which he's affectionately named "Lucille."

2. He Is Kind of a Big Deal

Negan isn't just a lone killer wandering the post-apocalyptic landscape. He has his own base of operations and a group of followers that call themselves "The Saviors." Like the Mafia, the Saviors survive by intimidating nearby settlements into paying tributes of food and supplies.

For all his wanton bloodlust, Negan does seem to have some sense of loyalty and attachment to his minions. Whether through fanatical devotion or fear, they follow his every order without question.

3. He Kills a Major Character

With his 2012 debut in issue 100 of "Walking Dead," Negan made quite the splash -- with Glenn's head.

He beat Glenn to death with Lucille, thereby killing off one of the series' longest running main players. One of the big questions surround the remainder of "The Walking Dead" Season 6 is whether Glenn will meet a similar fate. Glenn already had a close brush with death in the first half of Season 6. Even if he survives in this version, it's probably safe to assume some major character will be sacrificed at the altar of Negan.

4. A War Is Coming

After Negan's bloody debut, the "Walking Dead" comic eventually built towards a massive, 12-part storyline called "All Out War." There, Rick united the citizens of three different settlements in open war against Negan and the Saviors. It was a terrible conflict that resulted in many deaths and ushered in a completely new status quo for the series in the aftermath.

Will the series follow a similar path? Fans hope so.

5. He's a Bad Influence on Our Heroes

Part of Negan's appeal is that he's oddly charismatic, despite being a big fan of murder. His magnetic personality is partly the reason why he was able to rise to leader of his own settlement, and it also has an effect on both Rick and Carl in the comic. Both have struggled to maintain their humanity while feeling the pressure to handle problems in the Negan way, and Rick and our heroes may face similar struggles when Negan applies pressure on Sunday's premiere.