Pokémon/Pokédex/Gyarados

TM/HM

 * RB/Y/GS/C/RS/FL: Blizzard, Double Team, Fire Blast, Hyper Beam, Rest, Strength, Surf, Thunder, Toxic
 * RB/Y/C/RS/FL: Ice Beam, Thunderbolt
 * GS/C/RS/FL: Attract, Frustration, Hidden Power, Protect, Rain Dance, Return, Roar, Rock Smash, Sandstorm, Waterfall
 * C/RS/FL: Flamethrower
 * RB/Y: Bide, Body Slam, Bubblebeam, Double-Edge, Dragon Rage, Mimic, Rage, Reflect, Skull Bash, Substitute, Take Down, Water Gun
 * GS/C: Curse, Dragonbreath, Endure, Headbutt, Icy Wind, Sleep Talk, Snore, Swagger, Whirlpool, Zap Cannon
 * RS/FL: Dive, Earthquake, Facade, Hail, Secret Power, Taunt, Torment, Water Pulse

Shiny Gyarados
While all Pokémon have a shiny version, the crimson red shiny Gyarados is perhaps among the most famous shiny Pokémon due to its inclusion in the plot of the generation II games set in Johto.

Trading Cards

 * Base Set #6 - Gyarados
 * Team Rocket #8 - Dark Gyarados
 * Team Rocket #25 - Dark Gyarados
 * Gym Challenge #5 - Giovanni's Gyarados
 * Gym Challenge #13 - Misty's Gyarados
 * Neo Revelation #65 - Shining Gyarados
 * Skyridge #H10 - Gyarados
 * Skyridge #11 - Gyarados
 * EX Dragon #32 - Gyarados
 * EX FireRed & LeafGreen #109 - Gyarados
 * EX Team Rocket Returns #36 - Dark Gyarados
 * EX Deoxys #8 - Gyarados