That 4x Grass weakness is something every Omastar user needs to plan around. Swift Swim doubles its Speed in rain, which helps. Known as the Spiral Pokemon. The stat spread leans into special offense.
Defense and Sp. Atk carry most of Omastar's stat budget. Speed's the obvious dump stat. Tough to catch and yields 2 Defense EVs. Follows a medium-fast 1M XP curve.
Its sharp beak rings its mouth. Its shell was too big for it to move freely, so it became extinct.
Omastar Weakness
VulnerableOmastar's Rock/Water typing leaves it vulnerable to Grass, Electric, Fighting, and Ground moves. Grass hits land at 4x, so they're the biggest threat. 5 resistances help offset the weaknesses. Omastar's physical bulk (base 125 Def) helps cushion physical weakness hits, but special attackers are the bigger threat.
Evolved from Omanyte. Omastar is the final form in this two-stage line. No compatible partners for breeding via two egg groups. Eggs are slow to hatch. HP grew the most through evolution (+35 over Omanyte), and Omastar peaks at 495 total stats.
How to Evolve
Breed with Omastar to get Omanyte eggs from the Water1 and Water3 egg groups.
Ice coverage gives Omastar answers even while choice-locked. Choice Specs provides boosted special damage with move lock, and max Sp. Atk without Speed EVs with Shellarmor mean every prediction that lands hits hard.
Best Build
Let's Go Pikachu & Eevee uses different battle mechanics.
Competitive build content is not applicable for this game. Select a main series game for builds.
Leveling does the heavy lifting. Omastar picks up Hydro Pump and Blizzard along the way, building toward a complete offensive set. TMs add Normal and Dark coverage and more, but the foundation's already strong by then.
Level-Up Moves
TM Moves
Egg Moves
Tutor Moves
You're catching Omanyte first, not Omastar. Omanyte appears at moderate rates in the encounters below. The step cards map the full 2-stage line with evolution methods between each stage.
How to Obtain Omastar in Let's Go Pikachu & Eevee
Step 1Catch OmanyteCinnabar Island - Pokémon LabLet's Go PikachuGift from NPCLv.44LateWaterRevive Helix FossilCinnabar Island - Pokémon LabLet's Go EeveeGift from NPCLv.44LateWaterRevive Helix Fossil
Step 2Omastar ✓
Swift Swim changes the entire equation for Omastar. The 495 BST doesn't tell the full story. Ranked C-Tier as a wallbreaker.
Omanyte evolves into Omastar at level 40. Omastar is the fully evolved form. At 495 BST, it's got solid stats to work with.
Swift Swim is what you want on Omastar. Every competitive set worth running is built with that ability in mind. The alternatives (Shell Armor, Weak Armor) work on paper but Swift Swim is what makes Omastar worth using. On wall sets, Swift Swim pairs with Omastar's base 125 Defense to absorb physical hits on the switch.
At base 55 Speed, it won't be moving first often. On offense, Omastar is a special attacker with base 115 Sp. Atk. Defensively? Enough bulk to take a hit or two. Best used as a wallbreaker.
Omastar appears in 19 games, including Yellow, Red & Blue, and Gold & Silver.
One of the original 151, Omastar has appeared in 19 games — most mainline games. From Red & Blue through the latest titles, it's rarely been left out of a regional Pokedex.
- 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