Onix resembles a giant chain of gray boulders that become smaller towards the tail. There is a rocky spine on its head and a pair of black eyes right beneath it. This Pokémon has a magnet in its brain that serves as an internal compass. Its body absorbs many hard objects, making its body very solid. As it grows older, it becomes more rounded and smoother, eventually becoming similar to black diamonds.
Onix tunnels under the ground at over fifty miles per hour, which causes tremors and a terrifying roar that echoes a long way. The massive, winding tunnels it leaves behind are used as homes by Diglett. Onix loves to eat the large boulders it encounters while burrowing underground. As seen in the Pokémon Stadium series, Onix is capable of rotating its head, or any part of their body, a full 360 degrees. It is a very aggressive Pokémon that will constantly attack humans and Pokémon when it is in pain, as seen in the anime. Onix can be found in mountains and caves, though it prefers underground tunnels with little light.
Ash and his friends encountered a giantOnix in To Master the Onixpected. It was on a rampage until Bruno managed to get a Sandslash from under the Rock Snake Pokémon's "skin."
Bruno captured the Onix afterward.
The Crystal Onix featured a special Onix whose body is made out of glass crystal. Ash and his friends helped a glass sculptor named Mateo search for it because Mateo believed it would help inspire him to be better at his craft.
In Hello, Pummelo!, Drake of the Orange Crew owns an Onix and he used it to fight Ash's Squirtle in the second round in the Orange League Champion match.
Several Onix appeared in Tunnel Vision where they resided in the Onix Tunnel and attacked anyone who attempted to pass through it.
Janina, Jasmine's apprentice, has an Onix in the episode Fight for the Light. Her Onix was heavily coated in wax for protection against Water attacks.
A "King Onix" was featured in Hooked on Onix. Team Rocket tricked King Onix into thinking Ash and his friends were going to destroy his kingdom. When Ash managed to convince King Onix that he and his friends weren't bad by defeating it in a battle, Team Rocket tried to steal the royal Rock Snake Pokémon, but their plan was foiled, as usual.
Onix debuts in Onix is On! of the Red, Green & Blue arc as Brock's main Pokémon, however a picture of it is shown on a leaflet in Wanted: Pikachu!. Onix later continues to make appearances with Brock in various volumes onwards.
Bruno owns an Onix, on which he battles Bill, Lt. Surge and Red on Cerise Island. The Onix later manages to carry Bruno and Koga off the collapsing island. Another wild Onix was also seen on Cerise Island.
Onix is obtainable in a Poké Ball. Once thrown, it flies up into the sky and uses Rock Throw on the player's opponents. This will hit everyone on the field except Kirby if he uses his down special move.
Onix is the second Poké Float to appear. It provides a horizontally flat area all the time it is on-screen, though it becomes diagonal as it leaves the screen.
Game data
Pokédex entries
This Pokémon was unavailable prior to Generation I.
Onix has a magnet in its brain. It acts as a compass so that this Pokémon does not lose direction while it is tunneling. As it grows older, its body becomes increasingly rounder and smoother.
There is a magnet in its brain that prevents an Onix from losing direction while tunneling. As it grows older, its body becomes steadily rounder and smoother.
Onix is the largest and heaviest Pokémon that evolves once.
Onix is the only unevolved Pokémon that is used in the Pokémon World Tournament by Trainers beyond the right attendant.
Of all the Pokémon that can evolve, Onix has the highest base Defense.
When holding an Eviolite, Onix can reach a maximum Defense stat of 690. This is the highest Defense stat obtainable without the assistance of stat modifiers, Abilities or items with adverse effects.
Onix is most likely based on a combination of a snake and earthworm. It may also been based on the wyrm, a type of dragon that has been presented as limbless and burrowing.
This Pokémon article is part of Project Pokédex, a Bulbapedia project that aims to write comprehensive articles on each Pokémon species, as well as Pokémon groups and forms.
Hard Stone (5%)
For other sprites and images, please see Onix images on Bulbagarden Archives.
