In every game in which the Celadon Gym is present, an old man has appeared outside the Gym, cackling about the girls inside. In GenerationsIV and VII, his dialogue was changed to comment on the presence of "strong Trainers" instead.
The Celadon Gym first appeared in Pokémon Scent-sation!. Ash wanted to challenge the Gym Leader to a Gym battle, but the workers at the Gym refused to allow his entry because he had earlier insulted a perfume shop the Gym made perfumes for. With help from Team Rocket, Ash, in the guise of "Ashley", was able to enter the Gym. However, Pikachu saw through his disguise and Thunder Shocked him to reveal his true identity to everyone else. Ash then challenged Erika to a Gym battle, which she accepted.
However, the battle was interrupted by Team Rocket, who set off a bomb in order to cover their escape with what they assumed was the Gym's perfume's secret formula, setting the entire Gym ablaze. While most of the Pokémon inside were evacuated safely, Erika's Gloom was accidentally left behind, prompting Ash to enter the burning building in order to save it. After the fire was put out, Erika gave Ash a Rainbow Badge as thanks for saving her Pokémon, as well as revealing that Team Rocket had actually only stolen one of the perfume's ingredients, the essence of Gloom, much to the Rocket trio's dismay and disgust.
In Suffering the Flings and Arrows!, Ash, Goh, and Chloe visited the rebuilt Celadon Gym to attend a Pokémon flower arranging class held by Erika, who recognized Ash from the time he had saved her Gloom. Goh was hoping to use the flowers to make his Pinsir seem more appealing to his Heracross, who had started falling for the Lilligant that Goh had recently caught. Team Rocket also attended the course in disguises in the hopes of stealing Pikachu, but when no good chance to grab him without being noticed turned up, they abandoned their disguises and summoned the Rocket Prize Master. Pinsir defended Heracross from Team Rocket's Pokémon and defeated them, regaining Heracross's attention and admiration.
In the original series, the Celadon Gym is a giant greenhouse, where Erika's multiple Grass-type Pokémon wander around while they're not used for battles. In Pokémon Journeys: The Series, the greenhouse is a separate building from the Gym, and no Pokémon are seen wandering there.
Pokémon used in the Gym
One of Erika's battling Pokémon, Tangela is a strong Pokémon that manages to use its vines and Stun Spore in order to incapacitate the enemy. In its battle against Ash, it managed to take out Bulbasaur by using this combination. Erika then recalled Tangela when Ash sent out his Charmander.
Weepinbell was the next Pokémon Erika sent out to counter Ash's Charmander. Although Erika thought Charmander would be no match against her Grass-type Pokémon, Weepinbell's Razor Leaf was easily knocked away with Flamethrower, and while the Flycatcher Pokémon was dodging the flaming leaves, it was easily finished off with Skull Bash.
Gloom once saved Erika from a Grimer when she was a girl. From that moment onwards, they have become very close friends.
Erika used Gloom as her final Pokémon in her Gym battle against Ash Ketchum. With its horrid scent, it defeated Charmander easily. But before it could fight with Ash's Pikachu, a bomb placed in the Gym by Team Rocket exploded, setting the Gym ablaze.
Even though everyone managed to escape, Gloom was still trapped in the Gym surrounded by flames. Ash rushed into the Gym and rescued Gloom. In gratitude for saving Gloom, Erika gave Ash the Rainbow Badge.
Red was seen visiting the Celadon Gym in File 3: Giovanni. With his Fire-typeCharmeleon at a type advantage, Red was easily able to defeat Erika's Grass-type Pokémon, earning himself the Rainbow Badge.
The Celadon Gym debuted in Meanwhile...Vileplume!, where Erika requested Red to catch Eevee before she would accept his challenge for a Gym battle. When Red found out that Eevee was capable of changing freely between its evolutions and back, he immediately rushed to the Gym, suspecting Erika's involvement, and placed Eevee's Poké Ball into the Gym's healing machine. Before he could start the machine however, Erika appeared and challenged Red to a battle. Red's Saur and Poli didn't stand a chance against Erika's Pokémon, so Red switched for Pika, but even it struggled to withstand Erika's attacks. As Eevee was close to dying, Erika told that she'd give it a painless death. Red refused to accept this and had Pika use Substitute to distract Erika long enough so that Pika could get to the healing machine first. Seeing this, Erika congratulated Red of the well-fought battle and activated the healing machine, restoring Eevee's health. She then explained that she had merely been testing Red to see if he was a brave and trustworthy ally for the fight against Team Rocket, who had been the ones to manipulate Eevee in the first place. As a reward for showing his skills, Erika gave Red a Rainbow Badge.
The Celadon Gym, along with the rest of Celadon City, was attacked by Lorelei's army of Shellder and Cloyster. Erika fought against the attackers, preferring to immobilize them rather than hurting them. After Yellow defeated Lance on Cerise Island, the army lost all of its power and collapsed.
Vileplume was first sent out to defend Erika from an attacking Drowzee. When Erika fought Red, she used Vileplume against Pika, lasting a long time before Erika ended the match and awarded Red the Badge. She was later seen when Erika met up with Yellow.
Celadon Gym appeared in Celadon City, where Satoshi challenged Erika to a Gym battle, using his Charmeleon against Erika's Vileplume. As Charmeleon was blinded by Vileplume's Petal Dance, one of its Fire attacks accidentally set Erika's kimono on fire, and Satoshi had Charmeleon slash off the burning portion of the kimono before Erika could get hurt. Erika was about to be declared the winner, but she intervened, saying Satoshi had raised his Charmeleon well. She then rewarded Satoshi with a Rainbow Badge.
In the TCG
The Celadon Gym was featured in the TCG as both a Japan exclusive Theme Deck and as a card. The following is a list of cards named Celadon City Gym.
Related cards Cards listed with a blue background are only legal to use in the current Expanded format. Cards listed with a silver background are legal to use in both the current Standard and Expanded formats.
In Pokémon Yellow, if the player uses Cut on the bottom tree and battles the Cooltrainer directly north of it, after the battle, the cut tree will have respawned. If the player's Pikachu is present in the overworld, it will be standing on the tree. This won't prevent the player from using Cut on the tree, however.