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.
As it digs through the ground, it absorbs many hard objects. This is what makes its body so solid.
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.
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 60 breeding partners from the Mineral egg group. Pass egg moves like Block, Defense Curl, Dragon Tail and 4 more to offspring.
Onix doesn't rely on pure speed. Leftovers gives it passive recovery each turn to stay healthy, and Naive nature still pushes offense. Earthquake and the remaining moves keep the pressure on while max Sp. Atk and Speed EVs balance power and survivability.
Best Build
Best Onix Moveset
- Rest
- Ancient Power
- Earthquake
- Flash Cannon
Recommended Teammates
The natural movepool does the job, but Block and Defense Curl from the egg pool give Onix something extra.
Level-Up Moves
TM Moves
Egg Moves
Tutor Moves
Onix is available from early-game routes onward at high spawn rates. 14 encounter spots give you plenty of options. Grab one early and it'll be ready to evolve or train by mid-game.
Best Locations
14 walking encounters at Lv. 8-35 for Onix across Shield and Sword. A few locations are version-exclusive, so your copy of the game affects what's available.
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.
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. 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
