As a Pumpkaboo, she made her first appearance in The Bamboozling Forest!. While walking through a forest, Jessie tripped over Pumpkaboo as she was emerging from underground. While she kept shining her light repeatedly, Jessie threw a Poké Ball at her, successfully catching Pumpkaboo, much to James's surprise. Later, she was used to battle Ash and his friends to prevent them from rescuing a Pangoro and Pancham that Team Rocket had captured. Using her Leech Seed, Pumpkaboo was able to prevent her opponents' Pokémon from moving. She was defeated after Ash gave Pangoro a leaf, allowing it to regain its confidence and easily send Team Rocket blasting off.
Pumpkaboo appeared in The Clumsy Crier Quiets the Chaos!, using her flashlight ability to light up a cave for Jessie. They quickly ran into a wild Salamence, and Pumpkaboo and Jessie played dead in order to confuse it. While the Salamence tried to figure out what happened, Jessie put a device on its head. This caused Salamence to go into a rampage, sending Team Rocket blasting off. Pumpkaboo was later seen at the Pokémon Center, being healed of her injuries from Salamence.
In A Showcase Debut!, Pumpkaboo was used in the Coumarine Rookie Class Pokémon Showcase. Jessie dressed Pumpkaboo up as a scarecrow for the Theme Performance, where she was matched against Shauna's Bulbasaur and Alouette's Furfrou. Her costume and accessories were not well received by the audience members and she ended up receiving the least amount of votes, thus being eliminated from the competition.
In her first Showcase as a Pumpkaboo
In A Fork in the Road! A Parting of the Ways! she was separated from her Trainer as well as Wobbuffet after being blasted off by Pikachu. While looking for her with James and Meowth, she was captured by a Pokémon hunter along with Meowth and Inkay. After getting rescued by James and being reunited with her Trainer, she helped to defeat the Pokémon hunter along with Team Rocket's other Pokémon, Pikachu and Fennekin.
In A Relay in the Sky!, Pumpkaboo was used to compete in the Pokémon Sky Relay. She managed to finish her part of the race in first place by hiding inside an Altaria, but her team was disqualified when Meowth's Pelipper machine was exposed.
In A Festival Trade! A Festival Farewell?, Jessie met Count Pumpka who explained that her Pumpkaboo was rare in that it was a Super Size female and, as his own Pumpkaboo had fallen in love with her, asked her if she wanted to trade for his Mawile. Although Jessie initially refused, she was persuaded when she learned that Mawile had the potential to Mega Evolve. However, Pumpkaboo grew angry with her Trainer for agreeing to trade her away. Regardless, the exchange went ahead but when the Count sent out Pumpkaboo she promptly evolved into Gourgeist, the trade having triggered the evolution. Jessie soon regretted the trade and asked Count Pumpka if he was willing to trade back, and the Count agreed without any argument, as his Pumpkaboo was no longer interested in Gourgeist. After the trade, Jessie and Gourgeist were happily reunited, and Gourgeist was sent into battle against Pikachu. Regardless of her new form, Gourgeist was still defeated but this didn't matter to her or Jessie as the two were just happy to be together again.
In A Performance Pop Quiz!, Gourgeist was used in the Freestyle Performance of the Anistar Rookie Class Pokémon Showcase. Gourgeist used her flashlight ability as a spotlight while Jessie danced. Jessie finished her performance by having Gourgeist use Seed Bomb to create fireworks. In the end, however, Jessie did not receive enough votes and ended up in third place.
In A Dancing Debut!, Gourgeist was used, along with Wobbuffet, in the Freestyle Performance of the Couriway Rookie Class Pokémon Showcase. Gourgeist used Leech Seed to enwrap Jessie with vines, which resulted in a tower with Jessie on top. Next, Gourgeist and Wobbuffet helped the dancing Jessie to stay airborne. Gourgeist then used a combination of a Shadow Ball, reflected by Wobbuffet using Mirror Coat, and Seed Bomb to create fireworks, finishing their performance. In the end, their performance received the most votes from the audience, making Jessie the winner, earning her, her first Princess Key.
In An Explosive Operation!, Jessie sent out Gourgeist to protect Z2 from Team Flare. Gourgeist hit Mable's Weavile and Aliana's Druddigon with Seed Bomb, creating smoke, allowing Team Rocket to escape with Z2. Later, she fought Team Flare again along with Wobbuffet and Inkay. She attacked with Dark Pulse, but Weavile cut through the attack and hit her with Metal Claw. Although Gourgeist was able to subdue Aliana's Druddigon with Leech Seed, she and Inkay were then defeated by the Team Flare Grunts' Pokémon's combined attacks.
In Master Class is in Session!, Jessie used Gourgeist in the first round of the Gloire Master Class Pokémon Showcase, where she faced off against Nini's Smoochum and Concetta's Scraggy. Firing off multiple Shadow Balls resulted in beautiful sparkles and bursts of purple smoke. This performance gained the most votes from the audience, causing Jessie to advance to the second round. In the following episode, after Jessie had won in the second round, Gourgeist was used alongside Meowth in the semi-finals. She created massive tree-like roots using Leech Seed, while Jessie and her Pokémon danced around. The roots then formed a tower with Jessie on top and Gourgeist used Seed Bomb to create fireworks. After Meowth destroyed the roots with Fury Swipes, Jessie and her Pokémon landed on the ground, finishing their performance. In the end, however, Serena earned the most votes, causing Jessie to end up in Top 4.
When Team Rocket, Serena, Mairin, and Professor Sycamore infiltrated Lysandre Labs in XY134, Gourgeist was sent out, alongside Inkay, to battle Celosia's Drapion. Gourgeist was sent out in XY136 to fight the Megalith Zygarde, fending off its roots to clear the way for Ash and Alain. One of the roots, however, blasted Gourgeist and her Team members out of the helicopter, but they were saved by Diantha's Gardevoir.
In XY138, Gourgeist, along with her Trainer, Shauna, Serena, and their respective Pokémon, performed for a crowd of Lumiose citizens.
Since being caught Pumpkaboo has become Jessie's main battler in Kalos, replacing Wobbuffet. As is traditional for Pokémon owned by Team Rocket, Gourgeist has lost nearly every battle she has participated in.
While not as playful as James's Inkay, Gourgeist as a Pumpkaboo seems to be a very cheerful and energetic Pokémon; this can be seen when she often dances, spins around or sings during her battles, sometimes even childishly changing her tone of voice when attacking. She is shown to get excited and proud of herself when doing well in battle, such as in Forging Forest Friendships! when Ash's Hawlucha missed with Flying Press due to Pumpkaboo being a Ghost-type. She's also shown to have a tendency to flash her lights repeatedly as shown in The Bamboozling Forest!, when Pumpkaboo was startled by Jessie, though she used this ability to good effect in The Clumsy Crier Quiets the Chaos!. As a Gourgeist, she is shown to mirror her Trainer's mannerisms such as in Party Dancecapades!, when she mimicked Jessie's frustration at James' loss against Serena and Ash.
Her strong bond with her Trainer was displayed in A Festival Trade! A Festival Farewell?. She felt awkward when Count Pumpka's Pumpkaboo displayed affections for her, not feeling the same way, but got angry when Jessie considered trading her away and stubbornly entertained the Small Size Pumpkaboo's affections. Count Pumpka's Pumpkaboo rejected her after evolution and Jessie was angered, exclaiming that her Pokémon was caring and reliable. Gourgeist was overwhelmed with happiness to hear Jessie defend her and they reunited. The two of them continued acting affectionately in Over the Mountain of Snow!.