A colored background means that the Pokémon can be found in this location in the specified game. A white background with a colored letter means that the Pokémon cannot be found here.
The Reflection Cave made an appearance in XY037. Like in the games, it is filled with many reflective crystals. While traveling through the cave, Ash's mirror image suddenly seemed to come alive and grabbed Pikachu, prompting Ash to follow. He soon found out that on the other side of the Reflection Cave's mirrors, there was a Mirror World, where he met mirror versions of himself and his friends, all of whom possessed characteristics completely opposite to their real world counterparts: Ash was timid and easily shaken; Pikachu was sadistic; Serena was an arrogant and serious battler, who spoke in a Kansai dialect; Clemont was a fit and fast runner, who relied on magic instead of science; Bonnie was proud of her big brother's achievements; and Team Rocket were celebrated heroes of justice.
The real Ash soon learned that after losing a battle against Mirror World Serena, Mirror World Ash tearfully ran into the Mirror World's Reflection Cave, where he became separated with his Pikachu. After seeing the real Ash's Pikachu in a mirror, he reached out and grabbed it, believing it to be his own. After being reunited, Ash and Pikachu agreed to help find Pikachu's counterpart, which turned out to have been caught by Team Rocket, also having found their way into the Mirror World. As they began to attack the real Pikachu, both Ashes sent their Hawlucha to battle the them, but the real Hawlucha soon became confused by James's Inkay's Psybeam, and was quickly recalled before it started hurting its counterpart. Mirror World Ash's Hawlucha was quickly called back as well, being too cowardly and scared to fight Jessie's Pumpkaboo effectively. However, during the commotion, Mirror World Clemont sneaked behind the trio and freed the two Pikachu, who proceeded to send Team Rocket blasting off with a double Thunderbolt.
Afterwards, the real Ash managed to re-open the pathway between the real world and Mirror World, and barely managed to return back to his friends before the pathway was closed again, his friends and their Mirror World counterparts wished each other good luck on their journeys. Ash and his friends then exited the cave, deciding to find a Pokémon Center to spend their night in. The episode ended with the trio wandering the Mirror World forest before being found by their heroic counterparts.
