The powers of Chaos have found a new co-conspirator - and foe! In Chaos in the Old World: The Horned Rat, verminous hordes of Skaven have emerged from their Under Empire to challenge both the Old World and powers of Chaos for total domination. The Horned Rat is a new expansion for Chaos in the Old World, a strategy board game set in the Old World of Warhammer Fantasy Battles.