Insane Equals Violent: Sort of averted here. Ren is both insane and violent, but almost never at the same time. It's very scarce for him to perform acts of violence when he's having his psychotic Freak Outs. To the Pain monologues, on the other hand...
Intelligence Equals Isolation: Something he complains about in "Sven Hoek" and "Stimpy's Fan Club". Also, Stimpy seems to be his only friend and admirer.
It's All About Me: Ren is frequently selfish and inconsiderate (when not outright abusive) to Stimpy. This was a more nuanced vice in the Spumco made episodes, though took over his personality in many Games episodes.
Older than They Look: Pursuant to "I Was a Teenage Stimpy", he is much older than his best friend, maybe even around 60 years old in human age.
Ooh, Me Accent's Slipping: Billy West's voicing for Ren had a very erratic dialect to say the least. Kricfalusi had some moments too, but far more subtle.
Played for Laughs: Averted in most cases of his epic freak outs. When pushed to his mental limit, Ren becomes genuinely terrifying and disturbing. Some of them are quite dark for an ostensibly "kids cartoon"; it seems as though the aim of several of his freak outs weren't exactly to incite laughter from the audience, but for pure shock value. Take, for a good example, this scene where he very realistically descends into madness while contemplating murdering Stimpy.
Straw Nihilist: Would have been revealed to be one in the unmade episode "Life Sucks". He spends the whole episode telling Stimpy about the horrors of humanity and hammering into him that life is meaningless, horrible and stupid.
Strong Family Resemblance: Averted with Sven. He has some typical canine traits, but in general resembles Stimpy much more than Ren, both in terms of appearance and personality.
Ren's father would either resemble Ren physically, albeit taller (Ren Seeks Help), or look more like Sven (Hermit Ren).
Vocal Evolution: When Kricfalusi returned to voicing Ren in Adult Party Cartoon, his pitch was somewhat deeper and gravelier, with his resemblance to Peter Lorre being more blatant. Allegedly this was because Kricfalusi had trouble making his voice sound right via pitch shifting.
Stimpson J. Cat
Voiced by: Billy West (original series), Eric Bauza (Adult Party Cartoon)
"I'm hiding in the closet...like an idiot."
Steeimpy is an overweight manx cat with little brains (not as extremely little as, say, Ralph Wiggum) and a big heart. Despite having to deal with Ren's insanity and violence, he manages to put up with everything.
Ambiguously Gay: Prominent in the original series (unlike Ren, he was never portrayed as attracted to any female character, though the very first episode showed Stimpy as a chick magnet when he became famous), obvious in Adult Party Cartoon.
Ascended Fanboy: In 'Stimpy's Big Day', he wins a poem writing contest for the chance to meet Muddy Mudskipper, and becomes a big star in Hollywood, doing all sorts of TV shows and commercials.
Cats Are Mean: Subverted. Stimpy is a cat and possibly the nicest character on the show.
Characterization Marches On: In the pilot, Stimpy was more a slightly dopey prop for Ren to bounce off of, and barely had any speaking lines. The show quickly evolves Stimpy into an idealistic Cloud Cuckoo Lander who has almost as many limelight roles as Ren.
Genius Ditz: Well, he thinks of and creates his own inventions. Some of which actually work, although their level of usefulness to humanity is unimpressive.
Heavy Sleeper: Quite a few times. Ren would be awake at night and screaming, and not bothering Stimpy one single little bit!
Heterosexual Life-Partners: On Stimpy's side, however, this was highly debatable in the Nickelodeon days of the show, with many thinking that Stimpy was either asexual, bisexual with no proof, or just Straight Gay. Adult Party Cartoon confirms the last implication.
Mr. Horse is perhaps the Only Sane Man. But he might be the Ax-Crazy one, too. He was a doctor, a psychologist, a psychically unbalanced creep, a war hero, a spokesman for the United Nations, an airplane pilot and many, many more. Who knows what he really is?
George Liquor is an American so conservative, he thinks Republicans are communists. However, that part of his character was expanded in his own cartoon, The Goddamn George Liquor Program - in The Ren & Stimpy Show, he's portrayed as a man with a strong faith in rules and discipline. He's only made 2 appearances on the show, due to the Nickelodeon execs' absolute condemnation for the character.
Bowdlerize: His last name "Liquor" was censored with a Record Needle ScratchSound Effect Bleep in original Nickelodeon airings of the show due to the alcohol reference (according to Word of God, Nick also interpreted the name as a play on "lick her").
Catch Phrase: "What's this crap?!" and "HELLO! I'M GEORGE LIQUOR! AMERICAN!"
"A smart-mouth, huh? A smart-mouth!!"
Chuck Cunningham Syndrome: He made only two appearances in the show (one of which was banned for a long duration of time), Nickelodeon allegedly hated the character and were willing to let Kricfalusi take the rights to Liquor with him following his departure. A third Liquor appearance was planned for Adult Party Cartoon but only made it to storyboard stages by the time of its cancellation.
Knight of Cerebus: Victor is known for being the most malicious and unpleasant character who has probably appeared on the show. And probably, he and his father are the only true antagonists in the show.
Rambling Old Man Monologue: He's prone to this. In one episode, he's rambling to another old man who promptly dies. Cobb fails to notice and goes right on talking.
Really 700 Years Old: He rants about yanking off Thomas Jefferson's "silly powdered wig", suggesting that he was alive during the Colonial era. In another episode, he claims to have been there when the first prehistoric life-form crawled out of the sea, and that he was the one who killed the dinosaurs.