A person who fiends cack and needs this 24/7. A fiender of cack is usually male, because females are generally known to do this anyway. Cack fienders are often found in the wild on camping trips, especially in male only groups.
Person A: You fiend cack.
Person B: No I don't.
Person A: You were rubbing my cack in the tent last night, you are a fiend.
Person B: So you're saying I fiend cack?