If the Pokémon is burned, paralyzed, or poisoned by another Pokémon, that Pokémon will be inflicted with the same status condition.

If the Pokémon is in the lead spot, wild Pokémon are nearly-guaranteed to have its same nature.
The more mons the encounter is for, the less likely this effect will trigger.
1 enemy mon = 100% chance
2 enemy mon = Each mon will have a 66% chance
3 enemy mon = Each mon will have a 50% chance
4 enemy mon = Each mon will have a 40% chance
5 enemy mon = Each mon will have a 33% chance