Stench has a 10% chance of making the target flinch when hit by a damaging move used by the Pokémon with this Ability. Stench does not stack with King's Rock or Razor Fang, nor does it stack with moves that already have a chance to flinch. Each strike of a multistrike move has an independent chance of causing the target to flinch.
May inflict the Terrified status condition when the Pokémon is hit by a direct attack.* When the Pokémon is hit with a direct attack like Tackle or Scratch, the attacker is sometimes afflicted with the Terrified status condition!*
Stunky stands on its two front legs and a purple ball appears at the end of its behind. Stunky then flips around and fires the purple ball at the opponent, causing a purple, foul-smelling fog to appear and spread its stench for twenty-four hours.
Trubbish belches out a small olive-colored cloud from its mouth. When the cloud disappears, it spreads throughout the whole area and causes it to smell.
In Sliding Into Seventh!, Jeremiah's Skuntank was revealed to have Stench as its Ability, but the Ability activated off-screen. It appears to cause a lavender foul-smelling explosion.
In the manga
Pokémon Adventures
Stunky
The smell
The Pokémon releases a horrible smell from its body.
Stunky turns around and releases a small seed from its behind towards the opponent. When the seed hits the ground, it releases a horrible smell all around the battlefield. The smell lasts for twenty-four hours.