From Bulbapedia, the community-driven Pokémon encyclopedia.

Effect Spore (Japanese: ほうし Spore) is an ability introduced in Generation III that leaves spores on contact. Four Pokémon have this ability, all of them Grass-type. It has a 10% chance of inducing either Paralysis, Sleep or Poison on the opponent when hit with a physical attack. Interestingly, all the Pokémon who can legally learn Spore can have this ability, with exception of Smeargle.

Pokémon with Effect Spore

Single ability

As of Generation IV, no Pokémon have Effect Spore as their only ability.

Dual ability

Paras	Parasect	Shroomish	Breloom
Dry Skin	Dry Skin	Poison Heal	Poison Heal