This looks like The Master from the original Dr. Who.
Lady Diana is dressed as Lara Croft.
"off the hook" - originated as a way of saying that you're no longer a suspect in a case or that charges have been dropped against you. You are no longer restricted, you can move about freely. A party that is "off the hook" is a party without any restrictions on it - anything gose - and so a party you may wanna be seen at.
I wonder if there are actually Wonder Bread pajamas. I'm pretty sure there are pajamas out there with that sort of design.
Either the animators filmed this backwards, or the drivers are not from the U.S. - the cars on the forground of the establishing shot of the W Hotel drive from right to left, while those in the background drive from left to right. See the shot in the top half of this picture.
Later on, though, the cars are going the right way, as can be seen in the bottom half of the picture.
I used nigga for Butters' line, even though he obviously says "nigger," which is the second time the show has slipped that word past the censors. It was used the first time in "The Death Camp of Tolerance" to drive home how bad saying that word is, along with QUEER, BEANER, CHINK, HEEB, FAGGOT, CRACKER, SLOPE, and JAP.
Larry (played by Dahmer), Curly (played by Gacy) and Moe (played by Bundy) were the Three Stooges.
Cartman and Butters both use lines from NOTORIOUS B.I.G. Going Back To Cali
Cartman: "sippin' on booze at the House of Blues"
Butters: "I'm going going, back back, to Cali Cali. Uhh, yeah"
The costumes people wear: Jacks from Jack in the Box, Chiquita Bananas, nurses, (Rickle Me) Elmo, Bat-Man, Casper the Friendly Ghost, SpongeBob SquarePants, a Conehead, KISS, a cow, Denver Broncos, Spider-Man, Scooby Doo, Chef, Godzilla, Abraham Lincoln, a Muslim terrorist, a panda (Don't Sue People Panda, maybe?), Gilligan, Dr. Doom. One guest is dressed as a bag of McDonald's French Fries.
"Gaau!" - an interjection Napoleon Dynamite would often use in the movie of the same name.
Biggie Smalls fires off a lot of bullets, but fails to hit anyone. This implies that Biggie was a bad shot, and is dead because, well, someone was a better shot than he was.
The murderers dressed as chefs plotline is taken from the Three Stooges classic An Ache in Every Stake. The major change here is that the murderes kill the bakers instead of learning they quit.
Irwin's widow 'devastated' by South Park parody. She and the rest of Irwin's family are the only people who have a right to complain about the episode, since it can be seen as close to a personal attack as can be made without the victim of that attack being alive. As Satan said, it's just a little soon, you know?
There was no ex-lover, and the Catholic Church was the prominent religious organization.
MAJOR CHANGE (this will end up on the DVD): In the weekend airings, Bundy cuts off Dahmer's tongue instead of riping it out. Dahmer stabs Bundy in the base of the throat up through the brain, sawing his head in two. Bundy falls down. Gacy grabs a rolling pin and bashes Dahmer in the head with it, exposing brain tissue. Dahmer falls down, and Gacy is left alive, looking around quickly before it cuts back to the party.