The complete Pokemon RBY pokedex, part 9

Pokémon Name: Gengar
Type: Ghost/Poison
Classification: Shadow Pokemon
Pokédex Number: 094
Ability: Levitate
Useful Attacks: Nightmare
Location Found:
D/P/P: Old Chateau with R/S/E/Fr/Lg inserted
HG/SS: Evolve Haunter
Black: Trade, Poke Transfer
White: Evolve Haunter

The final stage of the Gastly line, Gengar is one sweet Ghost-type to keep around. The move set, the special attack stat and the overall design of the character make it extremely desirable. Get yours today!

Evolution: From Haunter via Trading