These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
"Journey to the Center of Cow": Cow accidentally swallows Chicken, who spends much of the episode paddling a river of acid inside Cow's four labyrinthian stomaches, encounter different enzymes of different intents, and in the end, not only does Red Guy (as a doctor) sacrifice his own life to save Chicken, he attends a disco rave with the enzymes. Wut?
"Intelligent Life?": Cow somehow builds a milk-powered rocketship out of cardboard boxes and metal trashcans, lands on a planet composed entirely of mud, meets Red Guy who claims to be an alien, brings him home where he's treated like a god, then later becomes a jean model (oh, and he models jeans to the same disco music from the above-mentioned rave)... then Chicken turns off the TV and comments how stupid that show was.
Some of Flem and Earl's fake flashbacks and Imagine Spots from "Lost at Sea" are pretty... odd...
"Monster in the Closet": Cow befriends a monster hiding in her closet, who's invisible to everybody except her, though he's obviously not imaginary, because Mom and Dad eventually see him, and order Cow to banish him to the closet out of fear of him; in the end, Chicken finds him in another closet (even though he was invisible to Chicken as well) and they become pals after Cow finally dismisses him as a figment of her imagination.
Ear Worm: Momma had a chicken! Momma had a cow! Dad was proud! He didn't care how!
The short piece of music that plays at an episode's Title Card. It will still be in your head years after you've watched an episode.
Moral Event Horizon: The Red Guy crosses this in the episode Part-Time Job when he tried to cook Chicken alive for his chicken-on-a stick restaurant.
They Copied It, Now It Sucks: Was accused of doing this to Ren and Stimpy, though, unlike most cartoons that tried to be as gross and shocking as Ren and Stimpy, this show actually had some former animators and storyboard artists who worked on Ren and Stimpy (the John K. episodes that weren't from Adult Party Cartoon), so it wasn't like the show hired a bunch of wannabes who had a passing knowledge of doing wacky, gross-out cartoons. They had people who knew from experience.
This Is Your Premise on Drugs: Inverted. This show could be seen as The Ren & Stimpy Show if it went to rehab and is in the process of recovering, but still has a long way to go before it can fully be clean (and traded its addiction to gross-out jokes for gender-bending jokes and sexual innuendo, similar to how most drug addicts turn to other addictions while trying to recover).
On a "Talkin' Toons Live" special, the first thing Rob Paulsen asks David Feiss (the show creator) was how much bong water was ingested before doing this show. The answer was none.