A Pokémon Nuzlocker is a trainer who undertakes the Nuzlocke Challenge, a self-imposed set of rules to add difficulty and emotional stakes to their journey. They can only catch the first Pokémon in each area, and fainted Pokémon are considered "dead" and must be released or boxed permanently. Nuzlockers often form strong bonds with their team, valuing strategy and creativity to overcome challenges, while storytelling and personal growth often play key roles in their journey.