Complete Monster: Iggins, the Big Bad of the second story in the trilogy. His vendetta against Gaz — which starts with sending assassins after her and her loved ones and escalates to using a Mind-Control Device to make her his slave (with some disturbing subtext to his intentions for her) — is all a result of Gaz taking his Game Slave 2 when they were kids. And he stole it from her in the first place. Oh, and when Dib and Zim attack his lair to free her, he first uses his own younger siblings as bodyguards, and when Zim gets past them, forces him to fight Gaz — which, seeing as Zim and Gaz are in a relationship by this point, adds a whole extra layer of Kick the Dog to that action. When Gaz breaks free of the mind control and proceeds to beat Iggins within an inch of his life, which renders him catatonic and promptly locked away in a mental institute, it is very satisfying to read.