Onix pre evolution: Stonix

Does Onix evolve into Steelix? - Quora

How to evolve Onix into Steelix in Pokemon Brilliant Diamond Shining Pearl - Dexerto

What is Onix's evolution chart? - Quora

Steelix Pokédex

What pokemon line do you think needs an evolution most? : r/pokemon

Onix pre evo by HappyHippowdon on DeviantArt

Fakemon w/Feral

Quirkid by Urbinator17 on DeviantArt

Venusaur - Characters & Art - Pokémon X and Y Pokemon venusaur, 151 pokemon, Original 151 pokemon

Onix (Pokémon) - Bulbapedia, the community-driven Pokémon encyclopedia

Soilix Onix Pre Evolution by Hyperagua on DeviantArt

9 Ways to Evolve Onix - wikiHow

What is Onix's evolution chart? - Quora