I may be stupid for looking for any sort of logic in a zombie show but, it drives me crazy that the severed zombie heads keep growling and moaning... Pretty sure you need lungs for that.
Rule 1: If you want to speak, you MUST be on the speaking rock. All agreed? Great. Rule 2: Only I get to be on the speaking rock. Any problems with that? I thought not.
(Knock at door) Terrified Koopa Troopa: "Wh.. who is it? A deep, powerful and angry response: It's-a-me, MARIO! (shoots fireball through door engulfing Koopa Troopa in flames)