Gourgeist's body resembles a brown Jack-o-lantern with two stubby legs, from which its light-brown neck protrudes, making it resemble a gourd. On top of the neck, there is a small face partially obscured by its long, peach-colored, hair-like arms.
Gourgeist come in four different variations: Small Size, Average Size, Large Size, and Super Size. The call of the Super Size version is deeper. Only Average and Super Size Pumpkaboo can have the Hidden Ability "Insomnia" which prevents them from falling asleep.
Shiny Pumpkaboo have a black pumpkin-body and purple arms.
At new moon, Gourgeist wander through towns in search for prey, singing with their eerie voice. Everybody who listens to the song is said to be cursed.
If it gets hold of its prey with its arms, it joyfully sings while enjoying the suffering of its victim.
In the Anime
In the Anime, the character Jessie has a Gourgeist which evolved from Pumpkaboo in the Episode Pokémon XY: Kalos Quest: A Festival Trade! A Festival Farewell?.