While most trainers evolve Onix into Steelix immediately, the unevolved form has a niche with Eviolite boosting its defenses. Electric moves can't touch it, which offsets the 6 weaknesses somewhat. Can go either physical or special depending on the set. Part of the Gen 1 roster.
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.
It twists and squirms through the ground. The thunderous roar of its tunneling echoes a long way.
It rapidly bores through the ground at 50 mph by squirming and twisting its massive, rugged body.
Onix Weakness
FragileOnix's Rock/Ground typing leaves it vulnerable to Water, Grass, Ice, Fighting, Ground, and Steel moves. 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.
- Dark and Steel types added — Fairy does not exist yet
- Moves are Physical or Special based on type, not per move
- Special stat split into Sp.Atk and Sp.Def
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.
How to Evolve
Breed Onix easily with 12 breeding partners from the Mineral egg group. Pass egg moves like Flail, Rock Slide to offspring.
Best Build
Gen 2 build content has limited support (no abilities).
Try selecting a different game/generation filter, or check back later.
The level-up pool is slim, so TMs matter here. Onix's Normal and Steel coverage all comes from technical machines, built on top of Earthquake and Dig for same-type damage. Earthquake and Iron Tail are the payoff moves.
Level-Up Moves
TM Moves
Egg Moves
Tutor Moves
Easy grab on Onix with high spawn rates across 16 locations in early-game routes. The sorted list below shows the full spread so you can pick the most convenient spot.
Best Locations
Before you go hunting for Onix, check which of the 16 spots belong to your version. Gold and Silver each have different walking and trade encounters at Lv. 6-48.
At 385 BST, Onix is firmly in pre-evolution territory. Evolve it into Steelix before bringing it to any serious fight.
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.
Onix evolves into Steelix while holding a Metal Coat. Onix is the base form of this evolutionary line.
Onix is leaning toward the physical side (base 45 Attack). Enough bulk to take a hit or two, too. But the speed tells the real story — base 70 Speed is workable — faster than some, slower than many.
Onix appears in 21 games, including Yellow, Red & Blue, and Gold & Silver.
Present since Red & Blue, Onix appears in 21 games spanning 9 generations. Gen 1 originals like Onix have the longest track record of availability in the series.
- Gen IY
Yellow - Gen IRBDebut
Red & Blue - Gen IIGS
Gold & Silver - Gen IIC
Crystal - Gen IIIRS
Ruby & Sapphire - Gen IIIFRLG
FireRed & LeafGreen - Gen IIIE
Emerald - Gen IVPt
Platinum - Gen IVHGSS
HeartGold & SoulSilver - Gen IVDP
Diamond & Pearl - Gen VBW
Black & White - Gen VB2W2
Black 2 & White 2 - Gen VIXY
X & Y - Gen VIORAS
Omega Ruby & Alpha Sapphire - Gen VIIUSUM
Ultra Sun & Ultra Moon - Gen VIISM
Sun & Moon - Gen VIILGPE
Let's Go Pikachu & Eevee - Gen VIIISwSh
Sword & Shield - Gen VIIIPLA
Legends: Arceus - Gen VIIIBDSP
Brilliant Diamond & Shining Pearl - Gen IXSV
Scarlet & Violet - Gen IXLZA
Legends: Z-A