To set the satirical and over-the-top tone for the remainder of the special, the opening dance number.
Pierre's Special Chrimbus Safety Message about frostbite, which gets progressively creepier as it goes.
Tthe ending of the Chrimbus Special, where Dee Vee sacrifices himself to give a Spoiled Brat one last copy of the Tim and Eric Chrimbus Special. When the doctor asks the father if it was worth killing a man, the father smiles and says, "I think it was." They hug anyway.
From the ending of the episode, continuing the episode's theme of 80's-style college films, Tim, Eric, and friends infiltrate Eric's parents' hotel to throw a party, only for, naturally, Eric's parents to come back early. So, everyone runs to the closet to hide as the two begin having sex... and then the rest of Eric's friends begin ogling the sight, and if that weren't bad enough, the two of them are fantasizing they're making love to Eric.
From Crows, The Dark Man showing Tim and Eric their cruelty against birds, set to jaunty infomercial music, and one such act includes the two of them beating up a man dressed in a chicken suit, who's advertising hot wings, with baseball bats.
"SPAGETT!" Or rather, the reactions to Spagett's "spooking," which tend to be more confusion than fright. A textbook example of Cringe Comedy.
The way they play off Spagett's popularity as an Ensemble Dark Horse by showing how terrible a Spagett movie would be. Terribly HILARIOUS!
The Man Milk episode is in both parts Nausea Fuel and a Crowning Moment of Funny, culminating in Tim and Eric failing to pasteurise their "man milk" and causing every one of their friends to die instantly from poisoning.
In Friends, Jan and Wayne Skylar trick Steve Brule on his 10th anniversary of broadcasting into thinking Wayne has passed away. Steve is absolutely distraught. Jan and Wayne then come in and shout "Surprise!" which causes Steve to have a total nervous breakdown. It's really fucking funny, if you don't find a harmless manchild breaking down completely a Tear Jerker.