Stats & Training
The stat bars tell the story: Defense carries everything and Sp. Atk's dead weight. But this Rock Snake Pokemon still yields 1 Defense EV per fight on a medium-fast 1M XP curve.
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 Weakness
Onix's Rock/Ground typing leaves it vulnerable to Water, Grass, Ice, Fighting, Ground, and Steel. Water and Grass hits land at 4x, so they're the biggest threat. It shrugs off Electric-type attacks completely. The Rock/Ground typing picks up 5 resistances to work with. Onix's physical bulk (base 160 Def) helps cushion physical weakness hits, but special attackers are the bigger threat.
| Damage | Types |
|---|---|
| 4x (Critical) | Water, Grass |
| 2x (Weak) | Ice, Fighting, Ground, Steel |
| 0.5x (Resist) | Normal, Fire, Flying, Rock |
| 0.25x (Resist) | Poison |
| 0x (Immune) | Electric |
- Dark and Steel types added — Fairy does not exist yet
- Moves are Physical or Special based on type, not per move
In Emerald, Starmie threatens a KO with Surf (437-515%). Claydol deals 73-87% with Earthquake.
 Magneton ElectricSteel | A | |
Recommended Build AbilityMagnetpull ItemMagnet NatureModest Moves View Magneton builds →
| ||
 Starmie WaterPsychic | A | |
Recommended Build AbilityNatural Cure ItemLeftovers NatureTimid Moves
Damage vs Onix View Starmie builds →Rapid Spin4-5% Ice Beam 2x145-172%KO Surf 4x437-515%KO | ||
 Claydol GroundPsychic | A | |
Recommended Build AbilityLevitate ItemLeftovers NatureAdamant Moves
Damage vs Onix View Claydol builds →Rapid Spin6-7% Earthquake 2x73-87% Explosion30-36% Psychic61-72% | ||
 Heracross BugFighting | B | |
Recommended Build AbilitySwarm ItemSalacberry NatureJolly Moves
Damage vs Onix View Heracross builds →Megahorn60-71% Rock Slide12-15% | ||
 Breloom GrassFighting | B | |
Recommended Build AbilityEffect Spore ItemLeftovers NatureJolly Moves
Damage vs Onix View Breloom builds →Mach Punch 2x42-50% | ||
Emerald Evolution
To get Steelix from Onix, you need a trade. The evolution method matters here. The evolved forms gain up to 125 total stats over Onix. View every chain in the Evolution Chart.
How to Evolve
Breeding
Breed Onix easily with 23 breeding partners from the Mineral egg group. Pass egg moves like Block, Explosion, Flail and 1 more to offspring.
Emerald Onix Best Moveset
Best Build
No build content available for this Pokemon in Gen 3.
Try selecting a different game/generation filter, or check back later.
Moves
The natural movepool does the job, but Block and Explosion from the egg pool give Onix something extra. Pair those with Earthquake and Dig for STAB and Normal and Steel coverage for reach, and the kit fills out nicely.
Level-Up Moves
TM Moves
Egg Moves
Tutor Moves
How to Get Onix in Emerald
No wild encounters for Onix in Emerald. It's available in Red, Yellow, or FireRed and can be transferred over. The details below show where to find it.
Onix is not available as a wild encounter in this game.
Catch in the wild in:
Then trade to Emerald.
Also found in:
Onix Guide
At 385 BST, Onix is firmly in pre-evolution territory. Evolve it into Steelix before bringing it to any serious fight.
In Emerald, watch for Starmie (Water), Exeggutor (Grass), and Cloyster (Ice) when using Onix. They all hit it super-effectively with STAB. Starmie is the most dangerous since Water moves deal 4x damage. Fighting, Ground, and Steel-type attackers are also a problem. With 6 weakness types, most competitive teams carry at least one counter.
Rock Head protects against recoil damage. That's the one you want on Onix. Weak Armor is the hidden ability. Niche, but it has its uses. Sturdy works too if your team needs something different.
Onix is a physical attacker with base 45 Attack. Enough bulk to take a hit or two, too. Speed tells the real story. Base 70 Speed is workable. Faster than some, slower than many.
In Emerald, For a casual playthrough, Onix works as a placeholder. Rock/Ground coverage is useful early. The real payoff is Steelix. That's where the stats start mattering.
Game Availability
Present since Red & Blue, Onix appears in 21 games spanning 10 generations. Gen 1 originals like Onix have the longest track record of availability in the series.
Click a game to view version-specific details
- Gen 1Y
Yellow - Gen 1RBDebut
Red & Blue - Gen 2GS
Gold & Silver - Gen 2C
Crystal - Gen 3RS
Ruby & Sapphire - Gen 3FRLG
FireRed & LeafGreen - Gen 3E
Emerald - Gen 4Pt
Platinum - Gen 4HGSS
HeartGold & SoulSilver - Gen 4DP
Diamond & Pearl - Gen 5BW
Black & White - Gen 5B2W2
Black 2 & White 2 - Gen 6XY
X & Y - Gen 6ORAS
Omega Ruby & Alpha Sapphire - Gen 7USUM
Ultra Sun & Ultra Moon - Gen 7SM
Sun & Moon - Gen 7LGPE
Let's Go Pikachu & Eevee - Gen 8SwSh
Sword & Shield - Gen 8PLA
Legends: Arceus - Gen 8BDSP
Brilliant Diamond & Shining Pearl - Gen 9SV
Scarlet & Violet - Gen 9LZA
Legends: Z-A - Gen 10WW
Winds & Waves