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 - Tom, 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 September 11th attacks (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: Joe Murray's first wife committed suicide shortly after season one aired. He spent less and less time working on the series, and ultimately gave up on it completely. For a time, he Mis-blamed the series for his wife's suicide. Murray's breakdown didn't affect the show's quality, but it is sad to hear.
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. The capital is Buenos Aires and it borders Chile to the west and south, Bolivia and Paraguay to the north and Brazil and Uruguay to the northeast. and British, and voices an Australian character.
Tom Kenny also lent his voice to several of the supporting cast of characters, including one of the Chameleon brothers, Really Really Big Man, and Peaches (some of which do sound like Spongebob, like the kid who yelled at Rocko for stealing his gum on the movie theater floor on "Popcorn Pandemonium"). Additionally, he also tends to be the voice behind many of the smaller characters who only make a single appearance in episodes.
Plankton (Doug Lawrence; credited as "Mr. Lawrence" on Rocko's Modern Life) is Filburt.
Series creator Joe Murray lends his voice as Ed's son, Ralph Bighead.
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.
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. 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. While both shows are good and have their share of fans, it does suck that Sniz and Fondue was never turned into a full series.
Joe Murray based Mrs. Bighead on a lady who lived in his neighborhood growing up, who was a smoker, and thus spoke with that incredibly raspy voice, as well as would continually try to come on to many of the younger men who lived in the neighborhood.
And, not surprisingly, Ralph Bighead was pretty much an Author Avatar for Joe.
Tom Kenny's voice for Heffer was an immitation of his nephew, whose voice was breaking at the time, as well as would regularly tell incredibly silly stories where he would end up laughing himself.
Heffer's eating habits also are based on Joe Murray's own struggle with binge eating during his teen years.