The show revolves around two cats—White Kitty and Black Kitty—who are both owned by a nameless little girl. Black Kitty, the jealous unfavorite, always tries to off White Kitty in a number of heinous and creative ways, but they all backfire violently.
Compare Happy Tree Friends, a similar series by the same studio.
Goodbye Kitty provides examples of:
- Accidental Hero: Brown Puppy.
- Accidental Murder: Black Kitty tries to murder White Kitty in one episode by tricking him into walking off a cliff. Instead, three girls end up falling off the cliff. Ultimately subverted when they survive.
- Black Comedy Rape:
- "Sun of a Bitch" ends with Black Kitty getting anally raped by a lion.
- Implied at the end of "Kittycide".
- Bloody Hilarious / Gorn: As expected, as it's from the same studio as Happy Tree Friends.
- Butt-Monkey: Black Kitty, oh, so much.
- Catchphrase / Title Drop: "Goodbye, Kitty!".
- Cats Are Mean / Cute Kitten: Black Kitty and White Kitty, respectively.
- Disproportionate Retribution: The entire reason Black Kitty tries so hard to kill White Kitty is out of jealousy. Subverted as the retribution in question never happens.
- Driven to Suicide: How Black Kitty finally manages to kill White Kitty in the season finale, appropriately entitled "Kittycide": by giving the girl a bunny for her birthday, with which she replaces White Kitty, who commits Seppuku. However, White Kitty is subsequently brought back to life by Black Kitty's Swiss Army Tears after realizing how much he actually misses him.
- Failure Is the Only Option
- Gang Bangers: One episode has Black Kitty attempt to get White Kitty killed by gangsters. Naturally, they decide to shoot Black Kitty instead.
- Hoist by His Own Petard: A lot of Black Kitty's deaths are caused by this.
- Idiot Ball: At least once. In the episode "Dance of Death", Black Kitty attempts to gas White Kitty with the old exhaust-hosepiped-to-car trick, only to be beset with the hose repeatedly popping out of the exhaust pipe. Rather than holding the pipe in, he chooses to inhale the exhaust to ferry it into the car itself. Unsurprisingly, he dies quite horribly indeed.
- Jerkass: Black Kitty.
- Also the girl, to an extent: she outwardly neglects Black Kitty in favor of White Kitty. In fact, she is actually aware of Black Kitty's constant failed attempts to kill White Kitty and resulting deaths, and is blissfully indifferent to it. Black Kitty ultimately proves her shallow affections by giving her a bunny in the season finale, leading her to start neglecting White Kitty as well. At this point, both Kitties decide that she isn't worth the trouble they go through, so they...
- Kick the Son of a Bitch: White Kitty and Black Kitty arrange to have the girl kidnapped by the Pedobear after she starts neglecting them both.
- Laser Guided Karmic Death: Every time Black Kitty tries to kill White Kitty.
- Only Known by Their Nickname: While White Kitty and Black Kitty are referred to in the episode descriptions as Goodbye Kitty and Black Cat respectively, neither one one has a confirmed name, though fans tend to use the former names. The fact that White Kitty is called such as a rock star helps.
- Precious Puppy: The brown puppy that sometimes show up.
- Road Runner vs. Coyote
- Rule of Three: Black Kitty usually makes three attempts on White Kitty's life per episode, and dies (or is at least maimed) as a result each time.
- They Killed Kenny Again: Black Kitty.
- The Unfavorite: Black Kitty.
- Voodoo Doll: One episode involves Black Kitty using this in an attempt to kill White Kitty. Unfortunately for him it ends up being turned into a Black Kitty voodoo doll when Brown Puppy covers it with black paint...subsquently he proceeds to rip it apart with his teeth causing Black Kitty a gruesome death.
- Wham Episode: The season finale. Black Kitty finally kills White Kitty, but realizes his life is not complete without White Kitty and brings it back to life. The two then determine their owner to be the true cause of their problems, take their sweet revenge on her, and decide to continue their usual routine under a much happier pretext.