Actor Allusion: In "An Elk for Heffer," after first meeting Elkie, Heffer is so flustered that he forgets his name. While trying to think of it, he lists several others— the first being Tom.note The other names are all from the production staff: Jeff ("Swampy" Marsh), Dan (Povenmire), and Joe (Murray).
Widow Hutchison is voiced by Kevin Meaney. And one point, she says "Turtles and cats together. That's not right."
"Leap Frogs," on the grounds of very sexual content. The episode centered on Bev Bighead trying to seduce Rocko while her husband is at work, as she feels that she's not being loved by Ed.
"Heff in a Handbasket": This episode was banned following complaints of the premise, which saw Heffer selling his soul to Peaches (the show's take on The Devil) and trying to win it back on a game show.
"Jet Scream": This episode didn't have any problems when it aired back in the 1990s, but when it reran on Nicktoons TV in the 2000s, it became one of many television shows that had to be banned and/or censored for sensitive material following the aerial attacks that occurred in New York, and Arlington, Virginia in September 2001 (in this case, it's because of scenes mocking airport security, Heffer being scared of flying, and the airplane nearly flying into a building). When the show aired on The 90s Are All That (the retro Nickelodeon block), the episode returned uncut and uncensored.
Creator Breakdown: Shortly after the first season aired, creator Joe Murray's first wife committed suicide. Murray had only planned to do one season, but when given the option, decided to do the other three, and for sometime blamed himself for not being there for her as a result. "Wacky Deli" is partially inspired by his failed efforts to get out of his contract with Nickelodeon so that he could have some time to grieve. The result was his complete lack of involvement in the forth and final season, after which he took some time away from the animation industry to get his personal life back together.
Crack Is Cheaper: most of the early merchandise from the show is extremely rare and expensive, Such as a set of plush dolls that usually demand prices of hundreds of dollars on ebay (if you can find them at all, that is)
Cross-Dressing Voices: Charlie Adler as Bev Bighead and Gladys the Hippo Lady. Adler's voice for Gladys the Hippo Lady (before she gets mad and yells, "How DARE you!") would later be used as the voice of Cow on Cow and Chicken. On the other hand, this is regulary averted in foreign dubs, when both characters are voiced by women.
Descended Creator: Mr. Lawrence was both one of the show's writers and Filburt. He actually got the job through a fluke. They had been having difficulty casting an actor. Mr. Lawrence had only done the voice while pitching jokes, but the writers liked it and suggested he audition. He eventually recorded a tape, but he left his name off it so that Joe Murray could remain impartial.
Development Gag: Joe Murray's only condition for doing the Musical Episode "Zanzibar" was that Rocko wouldn't sing, as he felt it was wrong for the character. This is why he's devolves into awkward mumbling whenever he's expected to by the other characters.
Executive Meddling: The many edits done to episodes that once aired uncut (including the ban on the episode "Leap Frogs.")
Fake Nationality: Carloz Alazraqui is Argentinean note from Argentina, a South American country. and British, and voices an Australian character.
Keep Circulating the Tapes: At least, before Shout! Factory picked up the rights, though if you have an uncut version of "The Good, The Bad, and the Wallaby" somewhere, circulate that to all who don't have the episode, 'cuz the part where Heffer gets sucked by the milking machine is not in the Shout Factory version. Same goes for the "berry picking" gag in "Hut Sut Raw" and the love motel scene in "Road Rash"; those are absent from the Shout! DVD sets and the Netflix episodes.
That said, the aforementioned "banned" episodes ("Leap Frogs," "Jet Scream," and "Heff in a Handbasket") are present and accounted for.
Out of Order: In "Who's For Dinner?", the fact that Heffer's family are wolves is supposed to be a big revelation. But that episode originally aired after "Bedfellows", where they play a semi-major role.
On Netflix, the episode containing "Carnival Knowledge" and "Sand in Your Navel" is the first episode when really it's the episode containing "A Sucker for the Suck-O-Matic" and "Canned."
All but Season Two were broadcasted out of order during the shows initial run on Nickelodeon; although in most cases the show was aired in the correct order during reruns, the DVD releases of Seasons One, Three, and Four place the episodes out of order again (since they are presented in original broadcast order, instead of chronological order).
The final episode was actually the second-to-last to air, only because the actual second-to-last episode was the Thanksgiving special, "Turkey Time," was withheld so it could air on Thanksgiving proper.
Star-Making Role: For both Carlos Alazraqui and Tom Kenny, who were unknowns when cast. Alazraqui has noted he told Kenny about the audition, so he has jokingly suggested he's entitled to a percentage of Kenny's paychecks on other projects.
Charlie Adler does the voices for Ed, Bev, and Mr. Dupette (Mr. Bighead's boss at Conglom-O and Rocko's boss when Rocko worked at the large comic book store, Super Lot-O-Comics). Lampshaded in one episode where Bev calls for her husband and snarks "What, am I talking to myself here??"
Then there is Tom Kenny voicing both Heffer and Peaches in "To Heck and Back" and "Heff in a Handbasket."
Joe Murray originally intended for Rocko be yellow, but Nickelodeon insisted that he be recolored a beige-ish color in order to appease the wishes of a toymaker that ultimately never produced any Rocko merchandise. The necessitated (further) alteration of the "Trash-O-Madness" pilot. While otherwise proud of the series, Murray claims that he has always hated Rocko's new color.
Mrs. Bighead also had blue hair in the original pilot.
Sniz and Fondue (the same series that appeared on KaBlam!) was originally going to be the fourth Nicktoon instead of this show. After this one got picked up, the former was going to be the tenth Nicktoon, but then along came a different show by one of the writers forRocko, at which point the network gave up on trying to bring Sniz and Fondue to series.
Rocko was originally going to have an older sister who he would occasionally visit whenever he needed advice and was a narcoleptic.
Joe Murray based the Bigheads on an older couple who lived next door to him as a kid. The wife was a smoker, resulting in a raspy voice, and often flirted with the younger men who lived in the neighborhood. Bev's hairdoo was inspired by Murray's own mother.
And, not surprisingly, Ralph Bighead was pretty much an Author Avatar for Murray himself. It actually took a bit of arm-twisting for him to voice the character, as he hates acting, but the rest of the crew insisted, if only because they thought it'd be funny to hear their otherwise monotoned boss raise his voice.
Tom Kenny's voice for Heffer was an imitation of his nephew, whose voice was breaking at the time and would regularly tell incredibly silly stories where he would end up laughing himself.
The character of Heffer was based on a childhood friend of Murray's, while his eating habits were based on Murray's own struggles with binge eating as a teen.