Unnatural Selection

Unnatural Selection is a gameplay achievement/trophy for Red Dead Redemption in which the player must "kill one of every animal species in the game in any game mode."

Animals can be killed as part of a hunting activity, generating income for the player.

To unlock this achievement/trophy, the player must kill each of the following animals at least once:
 * 1) Armadillo
 * 2) Beavers
 * 3) Bighorn Sheep
 * 4) Boars
 * 5) Bobcats
 * 6) Buffalo
 * 7) Chickens
 * 8) Cougar
 * 9) Cows
 * 10) Coyote
 * 11) Crows
 * 12) Deer
 * 13) Dogs
 * 14) Ducks
 * 15) Eagles
 * 16) Elk
 * 17) Fox
 * 18) Goat
 * 19) Grizzly Bears
 * 20) Hawks
 * 21) Domesticated Horses
 * 22) Wild Horses
 * 23) Mule
 * 24) Owl
 * 25) Pigs
 * 26) Rabbits
 * 27) Raccoon
 * 28) Seagulls
 * 29) Skunks
 * 30) Snakes
 * 31) Songbirds
 * 32) Vulture
 * 33) Wolves

Note: Press Pause > Stats > Misc to view a list of animals that you have killed, including how many. Animals that you have not yet killed will not show up in the list.

The name of the achievement is a parody of the theory of natural selection. Players must seek out and eliminate animals, intervening in the proposed natural process.

The Mule does not count towards the achievement.

Other Achievements
The player can complete this achievement in conjunction with the Bearly Legal achievement.