The Sauren is one of the 10 races available for play. It can be unlocked by killing special enemies, which sometimes will drop trophies. If playing with the Adventurer class, the trophy will have a 100% chance of unlocking any class & race, which may be the Sauren or any other race not already unlocked. If playing with another class than the Adventurer, the trophy will have a 50% chance of leveling that class up, and a 50% chance of unlocking a new class & race.
Unlocking the Sauren also unlocks the class: Rogue
Racial bonus: Search (double chance of getting a scroll in item shop)
Mortal enemy: Thief (steals 2 coins tiles each turn, or gold from your inventory if there's no coin tiles in play)
Mortal enemy effect: Damages you for 2x its attack value when it steals gold from your inventory