Alternative Character Interpretation: In "Kiss Me I'm Foreign," was Filbert taking his roll as Rocko's fake wife too seriously, or was he just playing it up because he knew the department of immigration would be watching?
Ass Pull: Played with in "Manic Mechanics". Rocko breaks his car, and all seems hopeless....until he notices a "Broken/Fixed" switch on the engine.
The scene with the naked fairies and the shaved voyeur gopher in "A Sucker for the Suck-O-Matic".
Heffer being abducted by aliens who look like him in the episode "Cruisin". Even though they went into the Bermuda Triangle and went through a time warp, this makes no sense in relation to the rest of the episode.
The following exchange in "Bye Bye Birdie" (which might be a quick example of Seinfeldian Conversation). Though they don't move there, Rocko and Heffer do go and visit France in a later episode:
Heffer: Hey Rock, do you want to move to France? (not taking eyes off TV) Rocko: Not really. No. (eyes also glued mindlessly to TV) Heffer: Yeah, me neither. (and they just continue watching TV)
In "Wacky Delly", when Ralph needs help from his dad, we briefly see what they're doing - Bev is being chased around the house by Ed, who is inexplicably inside a giant hamster exercise ball, and both are shrieking. The hell?
Cargo Ship: Canon: Spunky's forbidden romance with a mop.
The Psychiatrist was shown later to be wining and dining said mop.
And how does Spunky get over it? He falls in love with a fire hydrant!
Cult Classic: The show was never quite as popular as The Ren & Stimpy Show or SpongeBob at the time; the best it could manage was this. The cult fanbase, though, was enough so that the show was on MTV for a brief while.
If you believe the rumors about Family Guy, you could "Wacky Delly" as this with Ralph Bighead standing in for Seth Mcfarlane.
Growing the Beard: While season 1 was certainly funny, it was much more low-key, as it focused more on its Vanilla Protagonist Rocko. The show's evolution into an ensemble comedy not only brought the much funnier side characters center stage, but provided some of the funniest jokes, eventually leading to the excellent third season, which even Joe Murray agrees was the one where the show was really firing on all cylinders.
Harsher in Hindsight: In "A Sucker For the Suck-o-Matic", Heffer is channel surfing and we hear a reporter say this: "The official motorcade is just coming around the corner now, and... oh my God! There's a burst of gunfire!" This is really not funny considering the mass shootings of the '10s.
On April Fools' Day 2013, The 90s Are All That announced they'd air a lost episode of the series, which turned out to be a picture of mayonnaise. 3 years later, an hour-long special was announced. Looks like Rocko is back for real.
During production on season 2, Joe Murray's wife tragically killed herself. Murray later revealed that she was the one who made him more environmentally conscious and encouraged him to recycle, meaning that she was the inspiration for the much-loved Musical Episode "Zanzibar" a year later.
"Heff in a Handbasket," The episode where Heffer sold his soul to be on a game show, was once pulled due to its blasphemous content. Eventually, the episode did air again on June 6th, 2006 (6/6/06) on Nicktoons TV. Guess the Nickelodeon censors didn't see why would this be inappropriate.
In one episode, Filburt has a tube of a toothpaste-like substance called "Spirit Away". It's also funny if you're a Touhou fan, as Ran has a spell card called "Yukari's Spiriting Away".
One episode features Heffer choking to death, and the Grim Reaper comes and mockingly tells him he was killed by his own gluttony. Heffer cries, "I'M A GLUTEN!!!" This was a good long while before the anti-gluten diet craze.
Narm Charm: This is the whole reason "Zanzibar" is a musical. While Joe Murray is a self-proclaimed environmentalist, he was reluctant to do an episode about the environment out of fear that it would be too sentimental or pushy. The other writers convinced him that a Musical Episode would allow them to be tongue in cheek without harming their message, with Murray's only condition being that Rocko wouldn't sing, lest it be too silly.
Padding: The original "Trash-O-Maddnes" indie short, which is Murray's animated solo, is only five minutes long, so the broadcast version added new scenes from the overseas studio, and it's quite obvious which is which: the Murray animation is looser and has rougher audio, while the overseas animation is more on-model, has cleaner audio and doesn't much affect the plot.
Vanilla Protagonist: Rocko himself. He is the Only Sane Man of the in-universe in contrast to the much quirkier and inane side characters. Not coincidentally, when said side characters got more attention, the show became much more popular.
What Do You Mean, It's for Kids?: Aside from the hidden dirty jokes and crude humor (some of which has been cut from reruns), the show's deals with themes you'd find on adult cartoons like The Simpsons (back when it was the sitcom to watch to laugh at jokes about how hard modern life can be), such as infidelity, immigration, racism (shown as "animalism" on the show), death, and cults. This show even helped some modern kids in The New '10s grow up.
Rocko has his moments as well. For example, in the episode "Scrubbin' Down Under", he struggles to get a chunk of spinach out from between his teeth. His final attempt to do so? Use a fucking jackhammer. Predictably, he ends up in the hospital.