Chaos Gym is a Stadium Trainer card from the original Pokémon Gym Challenge set (2000). Its holographic art by Keiji Kinebuchi shows a neon-lit gym arena with bold pink and teal geometric design, capturing the set’s retro-futuristic style. In play, this card adds unpredictability by forcing a coin flip whenever a player tries to use another Trainer card, reflecting its “chaotic” effect. As part of the classic Kanto gym leader-themed Gym Challenge set, Chaos Gym is a nostalgic collectible that appeals to Pokémon TCG enthusiasts for both its unique game mechanic and vintage holographic artwork.