Onix is famous for being the longest Generation I pokemon, a title which it lost to its evolved stage, Steelix
, in Generation II. It can evolve into Steelix by being traded, while wearing a metal coat. It's notorious for being Gym leader Brock
's signature pokemon.
Onix makes its first television appearance in Showdown in Pewter City
, where Brock has it face Ash
. The Onix was later given to Brock's younger brother, Forrest, who later had it evolve to Steelix.
In To Master the Onixpected
, the Elite four member Bruno, visits the mountains to capture a giant Onix, who is much bigger than the even average Steelix. Bruno befriends and captures it after removing a Sandslash
which was bothering it.The Crystal Onix
featured a crystallized version of the giant pokemon. It was captured and defeated when Mateo unleashed its Charmeleon on it.