Stan runs away to visit Cartman's relatives in Nebraska. Meanwhile, Cartman's uncle and Charles Manson break out of prison, where they kidnap the kids and Manson learns the true meaning of Christmas.
"Merry Christmas Charlie Manson" contains examples of:
- Affably Evil: Charlie Manson.
- Bait-and-Switch: Kenny leaving with Charlie Manson for a more secluded part of the mall. Instead of killing him, Charlie just watches another Christmas special and has his tattoo redone.Stan: Hey, where's Kenny?
Charlie Manson: Oh, he's... around.
Kenny: [entering] Hey, guys. - Berserk Button: Do not tell Kyle Mr. Hankey isn’t real.
- Birds of a Feather: Almost all of Cartman's relatives are exactly like Cartman, to the point that they all act like him and use his catchphrases. Notably, Liane can clearly be seen and heard saying, "Aww, weak!" in unison with the rest of the family when the football broadcast returns after the news report on Charlie Manson's escape.
- Borrowed Catchphrase: Uncle Stinky says “Respect my authoritah” when he refuses to take the boys to the mall.
- Bratty Half-Pint: Despite his parents telling him not to, Stan sneaks out of the house to go on vacation with Cartman's family along with Kyle and Kenny.
- Christmas Episode: The Boys all go to Cartman's relatives in Nebraska for Christmas.
- Clothes for Christmas Cringe: The boys accompany Cartman as he visits his family in Nebraska for Christmas. Cartman is excited to get his present from his grandma until he opens it and it turns out to be a new shirt.Cartman: Mom, Grandma's gone senile! It's time to stick her in a home!
- Corny Nebraska: All of Nebraska is notably surrounded by cornfields.
- Darker and Edgier: The version of It's a Wonderful Life that Howard and Charlie Manson watch on TV in the basement.George Bailey: You just can't buy people, Mr. Potter. Why, you know what you are? You're a little bitch. That's right, you're a bitch, and I bet you'd like to suck it, wouldn't you?
- Fate Worse than Death: Staying in a house full of Cartmans is this for Kyle.
- Generation Xerox: Cartman's extended family is fat and repeats his various catchphrases.
- Heel–Face Turn: Charlie Manson through the power of Christmas specials.
- Holiday Pardon: Subverted. Stan goes with his friends to spend Christmas with Cartman's relatives when his parents said he couldn't go and he lies about them being dead. They decide to postpone his punishment until after Christmas.
- Jerkass: Howard Cartman. He takes his family hostage and even points a gun at his mother. It gets to the point where even Charlie Manson is lecturing him on etiquette.
- Never Bare Headed: This is the first time in the series where Cartman is shown without his hat.
- Noodle Incident: Apparently, riots starting at malls because a kids exposed the Mr. Hankey as a fake is a regular occurrence.
- Oh, Crap!: The Boys upon meeting Charlie Manson and then when they're running from the cops at the mall with him. The cops when Cousin Elvin throws a fudgesicle on the highway during the car chase and Stan when it turns out his parents found him in Nebraska.
- Only Sane Man: Stan is the only one who thinks going to the mall with Charlie Manson is a bad idea.
- Liane is the only member of the Cartman family that isn’t overweight or uses Eric’s catchphrases.
- Pet the Dog: Charlie Manson's speech to Stan about how his parents love him and wouldn't come all the way to Nebraska if they just wanted to punish him and make his life suck.
- Cartman inviting Stan, Kyle, and Kenny to Nevada despite his hatred of them counts as this.
- Police Brutality: The police gun down Kenny without a second thought for holding up a white flag in surrender, and beat and cuff him even when he's dead.
- Prison Rape: As Howard's getting arrested, his father tells him to watch out for this. Howard replies that he always does.
- Second Verse Curse: Invoked with Liane and Cartman who only know the first stanza of "Over the River and Through the Wood". They sing that for the entire car trip to Nebraska much to the annoyance of the other boys.
- Stock Footage: Real-life footage of Charlie Manson is shown during the news report on his escape.
- Shoot Him, He Has a Wallet!: Kenny tries to emerge from the house with a white flag and promptly gets gunned down.Police Chief: Look out, he's got a white flag!
- Shout-Out: The entire episode is more or less a Shout-Out to Christmas specials and has an in-universe one to How the Grinch Stole Christmas! in the form of The Grinchy Poo. The ending where everyone is singing "Hark the Herald Angels Sing" is also an obvious parody of the ending of A Charlie Brown Christmas.
- Shown Their Work: Both football teams that were playing the game Cartman's family were watching are real college football teams.
- That Was Not a Dream: Kyle wakes up screaming, saying he dreamed they were in a house full of Cartmans. After being told that's all real, he screams again.
- They Killed Kenny Again: Kenny holds out a white flag of surrender and is shot to death by the police. Instead of Stan saying "Oh my God, they killed Kenny!", we get Charlie Manson saying, "Oh my God, they killed the little orange coat kid."
- Title Drop: The Cartman family does this with the episode title when they make a surprise visit at Charlie Manson's cell at the end.
- White Flag: When the police storm the Cartman's residence because Charlie Manson is in there, Kenny is sent out with one of these. The police shoot him regardless.
- Would Hurt a Child: The Nebraska police have got no problem with clubbing rioting children and using tear gas on them. Not to mention riddling Kenny with bullets.
