On the night of December 15, 2006, an unlisted lost episode Family Guy aired on Fox. It was originally produced in 2006 as a Halloween special in season 5, but it was cancelled and shelved because Fox thought it was too disturbing and frightening.
They were right. No one knew this episode existed until it aired. The reason for why it randomly aired unannounced is unknown. It was rumored to have been a complete accident.
The episode was entirely in black and white, had terrible quality, extremely bad audio, and the animation was done horribly. When it came on, the Family Guy theme song didn't appear, instead just black screen and awkward silence. Then after about 30 seconds a random beating noise started, and soon a message appeared that said "September 8, 2006. Family Guy Episode X: The Black Dawn".
The first shot shows the Griffin's kitchen. Lois has finished making breakfast and she told Peter to call the kids. Chris and Stewie come downstairs but not Meg. In here, everyone seems either very depressed or angry and Brian oddly sits in the corner of the living room and doesn't talk. When Peter goes upstairs to get Meg, he sees her naked cutting herself and drinking her own blood. He calls her name, and she starts running towards him and slits his throat.
Pretty soon Peter dies and Meg shoves him in her closet. The family hears Peter fall to the floor and rush to see what happened. They see Meg covered in bloody razor blade cuts. Lois asked what happened to her and then Peter falls out of the closet because Meg didn't do a good job putting him in there. The family is in shock and Lois starts heavily sobbing. Meg then grabs an ax hidden under her bed and chops Lois' head off. She takes a bite out of her head.
Stewie and Chris run downstairs to escape, they try to warn Brian who's still sitting in the corner of the living room. He just ignores them, when they call him again, his head turns all the way around and he has a very creepy smile on his face. He looks possessed. He then tries to attack them. He chases them to the kitchen where Stewie grabs a knife and stabs him in the heart. Chris appears to be upset about what Stewie did, but he tells him he had no choice and quickly forgives him.
Meg comes downstairs and chases them outside, they go and hide in the Swanson's house. They tell Joe about the situation. He then tries to deal with her but she chops him with her ax and does the same to Bonnie. Chris and Stewie escape to their basement.
A few days later they come out and see that nearly everything has been destroyed. They find an newspaper and find that a virus broke out and the zombie apocalypse came. They stand in the middle of the road where there's nothing but dead silence. They then see Meg and several other zombies including Peter and Brian and the neighbors charging toward them.
They also find a chainsaw lying on their front lawn. Stewie grabs it and starts killing zombies with it. Meg is the only one left still alive, but Stewie sees that Chris was killed by the zombies with his face eaten off. Stewie gets distracted by this and then gets killed by Meg. At this point, the quality gets even worse. Meg then takes her ax and accidentally chops her own head off. Then the scene pans out and cuts to static and the episode ends.