In the Manglewood Forest.

Gengar sneaks through the brush, stalking an unsuspecting Caterpie to scare. When the time was right, he jumped forward and jumpscared the little Pokémon, making it scurry away in fear. He cackled and laughed, enjoying his fearful it was. He was startled, however, when he suddenly heard the sound of singing in the distance, a lovely hummed lullaby. "...Gen..? Gengar..?" He mutters to himself as he crept towards the area where he hears the singing.