What does the Hasty nature do?

Hasty raises Speed by 10% and lowers Defense by 10%.

What stat does Hasty increase?

Hasty increases Speed by 10% and decreases Defense by 10%. HP is unaffected.

A Hasty Pokémon likes Sweet flavors (tied to Speed) and dislikes Sour flavors (tied to Defense).

Yes. Use a Hasty Mint to apply the Hasty stat effect to any Pokémon without changing its displayed nature.

Nature

Raises Speed, lowers Defense.

Raises Speed +10%

Lowers Defense −10%

LikesSweet

DislikesSour

Fast mixed attackers that won't survive physical hits anyway.

Timid −Attack Jolly −Sp. Atk Naive −Sp. Def

What does the Hasty nature do?: Hasty raises Speed by 10% and lowers Defense by 10%.
What stat does Hasty increase?: Hasty increases Speed by 10% and decreases Defense by 10%. HP is unaffected.
What flavor does a Hasty Pokémon like?: A Hasty Pokémon likes Sweet flavors (tied to Speed) and dislikes Sour flavors (tied to Defense).
Can I change a Pokémon to Hasty?: Yes. Use a Hasty Mint to apply the Hasty stat effect to any Pokémon without changing its displayed nature.