|Current Status||With Forrest|
|Where Obtained||Pewter Gym, Pewter City, Kanto (by Brock)|
|Poké Ball||Poké Ball|
|Alternate Counterparts||Steelix (games)|
|First Appearance||Showdown in Pewter City|
|When Evolved||Sometime between A Family That Battles Together Stays Together! and Grating Spaces!|
|Voice Actor||Unshō Ishizuka|
Steelix was Brock's starter Pokémon.
Steelix is very loyal to Brock and reflects his personality quite closely.
Onix has been shown to be morbidly afraid of water. In a race, Onix kept up a top three position until they hit a body of water and were forced to retire, causing Onix to cry in disappointment. When necessity forced him to expose himself to water when damming the Cinnabar volcano, Onix only permitted the tip of his tail to be soaked. It is unknown if Steelix retains Onix's hydrophobia.
|Tackle||Showdown in Pewter City|
|Bind||Showdown in Pewter City|
|Dig||Clefairy and the Moon Stone|
|Rock Throw||Who Gets to Keep Togepi?|
|Sandstorm||Entei at Your Own Risk|
|Slam||A Family That Battles Together Stays Together!|
|Iron Tail||Grating Spaces!|
|Dragon Breath||Grating Spaces!|