Red: Under a full moon, this POKéMON likes to mimic the shadows of people and laugh at their fright.Yellow: A GENGAR is close by if you feel a sudden chill. It may be trying to lay a curse on you.Gold: It steals heat from its surround ings. If you feel a sudden chill, it is certain that a GENGAR appeared.
Prof. Lotus' Notes: Gengar's name origin possibly comes from the German word, Doppelgänger. The longstanding theory is Gengar is Clefable's shadow, they share many physical traits, that with the addition of Fairy type makes Gengar strong against Clefable. The even darker theory is Gengar is the ghost of dead Clefable.