Brace yourselves, “Walking Dead” fans. You may not be able to sleep after actor Jeffrey Dean Morgan makes his grand entrance as comic book villain Negan in the Season 6 finale of the hit AMC zombie series.

Morgan, 49, made his debut as Negan in the trailer for episode 16. However, viewers only managed to catch a quick look at the back of him. Despite the character still being in the dark, those who have read Robert Kirkman’s graphic novels know that Negan is a very dangerous and deadly man.

Negan is the leader of the Saviors and is described as charismatic. A used car salesman prior to the zombie apocalypse, Negan now rules with an iron first, or rather, a baseball bat wrapped in barbed wire. Negan demands that other survivors give him supplies, weapons and food in exchange for “protection.” He punishes people by using the bat, named Lucille, to beat in their heads. He also inflicts punishment by using an iron to burn the faces of men who disobey him.

“You know ... Just get ready, man,” actor Andrew Lincoln told Entertainment Weekly about Negan’s introduction. “I read the script and I went, ‘This is the greatest entrance ever written.’ ”

Because of the comics and other leaked reports, it’s rumored that Negan will kill one of the Alexandria survivors in the Season 6 finale. Although there is some speculation about who may be the unfortunate one to bite the dust, the network is keeping tight-lipped about the potential fatality.

“Walking Dead” fans are bound to be in shock after tonight. To help viewers recover, we’ve rounded up some of Jeffrey Dean Morgan’s sweetest and least scariest lines from his movie and TV roles over the years.

  • “There’s no man, alive or dead, who’s going to fault you for living.” — William in “P.S. I Love You”
  • “I don’t think I ever told you this, but ... the day you were born, you know what I did? I put a hundred bucks into a savings account for you. I did the same thing for your brother. It was a college fund. And every month I’d put in another hundred dollars. Until ... Anyway, my point is, Sam, that, this is never the life I wanted for you.” — John Winchester in “Supernatural” Season 1, episode 20
  • “Look, I don’t expect to make it outta this fight in one piece. Your mother’s death? It almost killed me. I can’t watch my children die too. I won’t.” — John Winchester in “Supernatural”
  • “I just want you to know that I’m proud of you.” — John Winchester in “Supernatural” Season 2, episode 1
  • “This cake is fantastic. You mix these two together, it tastes just like a Ring Ding.” — Patrick in “The Accidental Husband”
  • “I’ve been lying in this bed for close to a year, and I’ve had a lot of time to look back on my life. And the things that I remember best — those are the things that I wasn’t supposed to do and I did them anyway. The thing is, life is too damn short to be following these rules.” — Denny Duquette in “Grey’s Anatomy”