Hello! Im just wondering, would a pokemon outlive its trainer or would it be the other way around. How long is the average lifespan of pokemon in human years?

It really depends on the species. Most ghost-types, some steel, and a number of rocks can live for centuries or even millennia. Some specimens, such as one particular giant haunter nicknamed Black Fog, have even been around since the old empires. Such pokémon either gain new trainers after their old ones pass or simply return to the wild.

On the other hand, a lot of animal-like pokémon, especially rodents, smaller birds, and insects, might be lucky if they reach twenty years of age. Keeping a pokémon in a poké ball and evolution can help (a ball suspends most of a pokémon’s bodily functions, including aging, while evolution boosts their vitality and strengthens them physically), but even with these measures, it’s unlikely that these pokémon will outlive their owners unless their owners are already old.