The following are outfits found in Undead Nightmare. Many of these outfits are from the main Red Dead Redemption game. Five are available right away and four are unlocked during Undead Nightmare. The Legend of the Apocalypse and Undead Hunter outfits require you to complete a number of tasks to unlock.
Note: Only the Undead Cowboy Outfit, Legend of the Undead Outfit, and Army of the Undead Outfit, are available after the mission(s) A Civilized Man/On a Pale Horse.
Find and break the mythical unicorn. It is located northwest of Torquemada. - You have to first find and kill the legendary Chupacabra and break the Four Horses of the Apocalypse.
BENEFITS:
You will unlock a "Holy Relic" that appears in your inventory. Once a day, you can take this and replenish your ammunition and receive consumable items.
Legend of the Apocalypse or Legend of the Undead
HOW TO OBTAIN: Complete the following requirements to unlock the suit:
Complete all four Undead Challenges. There are 5 levels to each challenge.
BENEFITS:
This outfit increases the duration of phosphorus bullets.
Undead Cowboy Outfit
HOW TO OBTAIN:
Unlocked at the end of the game.
BENEFITS:
Allows you walk amongst the dead, until you get too close to the zombies.