PoisonDark
Poison and Dark types: weaknesses, resistances and Pokémon
Poison and Dark Pokémon take double damage from Ground moves, resist Grass, Poison, Ghost and Dark moves and are immune to Psychic moves.
With 5 resistances and immunities against 1 weaknesses, it is a very solid defensive combination.
Poison moves are super effective against Grass and Fairy and not very effective against Poison, Ground, Rock and Ghost. Dark moves are super effective against Psychic and Ghost and not very effective against Fighting, Dark and Fairy.
To beat these Pokémon, your best pick is Ground moves. Avoid Grass, Poison, Ghost and Dark moves, which deal little or no damage.
There are 4 Pokémon with this combination, such as Stunky, Skuntank, Drapion and Overqwil.