No, but:
>...From Emerald onwards, if the Pokémon with the Ability Synchronize is leading the party, there is a 50% chance of encountering a wild Pokémon with the same nature.
Source: Bulbapedia
So, lets say you want a Modest Liwick. If you have an Espeon with a Modest nature, you can go to Celestial Tower and you have a 1 in 2 chance of finding a Modest Litwaick.
