Pokémon/Pokédex/Onix

How to Evolve
Onix evolves when it is traded with a Metal Coat. (Note: If the recipient is playing Pokémon FireRed or LeafGreen and has not received the National Pokédex, the evolution cannot take place.)

TM/HM

 * RB/Y/GS/C/RS/FL: Dig, Double Team, Earthquake, Rest, Strength, Toxic
 * GS/C/RS/FL: Attract, Frustration, Hidden Power, Iron Tail, Protect, Return, Roar, Rock Smash, Sandstorm, Sunny Day
 * RB/Y: Bide, Body Slam, Double-Edge, Explosion, Fissure, Mimic, Rage, Rock Slide, Selfdestruct, Skull Bash, Substitute, Take Down
 * GS/C: Curse, Endure, Headbutt, Mud-Slap, Sleep Talk, Snore, Swagger
 * RS/FL: Facade, Rock Tomb, Secret Power, Taunt, Torment

Breeding

 * GS/C/RS/FL: Flail, Rock Slide
 * RS/FL: Block, Explosion

Trading Cards

 * Base Set #56 - Onix
 * Gym Heroes #21 - Brock's Onix
 * Gym Heroes #69 - Brock's Onix
 * Neo Genesis #69 - Onix
 * Aquapolis #98 - Onix
 * EX Sandstorm #71 - Onix
 * EX FireRed & LeafGreen #42 - Onix
 * EX Team Rocket Returns #69 - Onix