Ass Pull: Played for Laughs. Poochie is sloppily killed off in one cartoon, with a crude movement of cels and stuck on note saying he died on the way to his home planet. Everyone hated Poochie so much they didn't care, they erupted in applause.
Designated Monkey: In a parody of standard cat and mouse cartoons, Scratchy is brutalized just because he's the cat.
Dude, Not Funny!: Often from Marge, though there are episodes that touch a nerve with even Bart and Lisa, albeit usually connected with some dilemma they are undergoing at the time.
Hilarious in Hindsight: In "The Tears of a Clone", Scratchy has died, and Itchy realizes that Victory Is Boring and life is meaningless without his Arch-Enemy around, so he creates a cloning machine and creates more clones of Scratchy so he can kill them. However, he grows tired because of the way the machine spits out clones, so Itchy creates a killing machine and makes an endless slaughterfest. Over fifteen years later, we get the Treehouse of Horror XXVI segment "Wanted: Dead, then Alive", whose plots became strikingly similar to "The Tears of a Clone", with Sideshow Bob as Itchy and Bart Simpson as Scratchy; the Reanimator in place of the cloning and killing machines; and a slightly different ending, which goes well with Bart and his family finally triumphing over Bob after all the ordeals the boy has gone through.
Jerk Sue: Parodied and exaggerated. Not only does no one else in the cartoons mind Itchy brutalizing Scratchy (and sometimes others) but it's very incarnation of God sides with him and helps kill Scratchy and sends him to suffer in hell.