Gengar

Gengar is one of only two famed OU veterans that have been OU for all five generations. It owes this to its excellent Special Attack and Speed stats, immunities to Ground-, Normal-, and Fighting-type attacks and to the poison status, as well as a concise movepool that grew with each passing generation. This generation, the only thing it gained was a 100% accurate Disable, as well as Dream World-exclusive competition from Chandelure. Gengar is now perhaps best known for its SubDisable set, with which it can dismantle many Fighting-types, be they the old favorites Lucario and Infernape, or new introductions such as Terrakion and Conkeldurr. In Dream World, however, Gengar's Pursuit weakness is compounded by its ability to be trapped and OHKOed by Choice Scarf Chandelure if it isn't wielding a Choice Scarf itself. Both these threats cripple Gengar, but it is still very useful in the Dream World metagame.