Everybody knows that Red Dead Redemption made the Old West even cooler. But what makes Red Dead Redemption even cooler? That is correct! Zombies. Even better: everything is zombies including bears, birds and coyotes. What could possibly top that you ask? If you said the Four Horse Men of the Apocalypse, you would be correct. The Undead Nightmare pack released today, and we just happen to have a trailer to share with you.