Onix (Japanese: イワーク Iwark) is a Fighting-type Basic Pokémon card. It is part of the Diamond & Pearl expansion.
Headbutt is a move in the Pokémon games that Onix can learn via TM02 (in Generation II) or Move Tutor (in Pokémon HeartGold and SoulSilver). This card's Pokédex entry comes from Pokémon Diamond.