Board Thread:Questions and Answers/@comment-39812025-20190614230700/@comment-29956323-20190615074202

There is no place in game where Gastly would be that low level. Even during halloween event you would be encountering Gengar and not Gastly. However, once you unlock cinnabar island (7th gym area), you can access the move relearner on 2 island to learn moves you would learn via level up