#0139 · Kanto · Generation 1 · fossil

Omastar

Spiral Pokémon · Rock/Water-type

Omastar is a Rock/Water-type Pokémon, the Spiral Pokémon, number 139 (#0139) in the National Pokédex. It was introduced in Generation 1 and comes from the Kanto region. It is 1 m tall and weighs 35 kg.

Omastar is the Spiral Pokémon in its full ancient form, a Rock and Water hunter with a ring of crushing fangs and tentacles that work like hands. The Pokédex blames its extinction on a shell that grew too large and heavy.

How to pronounce Omastar

Omastar is pronounced OM-uh-star. The capital letters show the stressed syllable.

Listen to Omastar said out loud:

In Japanese it is オムスター (Omstar).

Hear every other name on the Pokémon pronunciation guide.

Lore

Biology

Omastar is 1 m tall and 35 kg. Bulbapedia describes a sky-blue body, a pale yellow spiral shell lined with sharp spikes, and a mouth ringed by a four-part beak. The Pokédex says its tentacles are so developed they work like hands and feet, and that its sharp fangs could crush rock.

Behaviour

The Pokédex says Omastar wraps its prey in its tentacles and, once it has hold, never lets go. Its big, heavy shell made it slow, so it could attack only prey that came within reach of its tentacles.

Habitat

Bulbapedia says Omastar swam the seas in prehistoric times, and its habitat category is Sea.

Diet

The Gold Pokédex says it cracked Shellder's shell with its fangs and sucked out the insides.

Powers

Like Omanyte, Omastar can have Swift Swim or Shell Armor, with Weak Armor hidden. It adds Crunch for its fangs, and by TM it can learn Earth Power and Stone Edge. Base Defense 125 and Speed 55 make it a heavily armoured but slow special attacker.

Name origin

Omastar may combine 'ammonite' with 'star', perhaps for its star-like body and shell. The Japanese name is Omstar (オムスター), which may blend ōmugai ('nautilus') with 'star'.

Design inspiration

Omastar is based on an ammonite. Bulbapedia suggests that its habit of gripping prey and cracking shells with a ring-shaped mouth may also recall Anomalocaris, an ancient sea predator, and again the nautilus.

Evolution notes

Omastar evolves from Omanyte at level 40. The Ultra Sun Pokédex says it is apparently a distant ancestor of Octillery.

In the games

In Mystery Dungeon: Explorers of Time and Explorers of Darkness, Brine Cave is guarded by two Omastar and a Kabutops, who act as its bosses. Omastar has been the evolution of a fossil-revived Omanyte since Generation I, appears in the wild in Sword's Expansion Pass areas and in Max Raid Battles, but is unobtainable in Scarlet and Violet and in Legends: Z-A.

In the anime

Two Omastar debuted in 'Attack of the Prehistoric Pokémon', woken in Grampa Canyon with the other Kanto fossil Pokémon. In 'Dealing With Defensive Types!', one catches Team Rocket stealing food in the Canalave Gym kitchen and blasts them off with Water Gun.

Fun facts

• Its base Special Attack of 115 is the highest of any Water or Rock type introduced in Generation I, according to poke.si's game data.
• Several older Pokédex entries state flatly that its heavy shell caused its extinction, but Sword's entry says only that some people say so.
• An Omastar belongs to a group of Pokémon hunters in 'The Wild Pair, Friede and Cap!'.

Sources: Bulbapedia: Omastar (Pokémon) · Serebii: Omastar (Sword/Shield Pokédex)

Base stats

• HP: 70
• Attack: 60
• Defense: 125
• Sp. Atk: 115
• Sp. Def: 70
• Speed: 55

Omastar’s base stat total is 495. Its highest stat is Defense.

Type matchups

What is Omastar weak to?

Omastar takes extra damage from Grass (4×), Electric (2×), Fighting (2×), Ground (2×) moves.

It resists Fire (¼×), Normal (½×), Ice (½×), Poison (½×), Flying (½×).

Evolution

What does Omastar evolve from?

Omastar evolves from Omanyte at level 40.

Omastar is the final stage of its evolution family.

The whole family: Omanyte, Omastar.

Abilities

• Swift Swim: Doubles Speed during rain.
• Shell Armor: Protects against critical hits.
• Weak Armor (hidden ability): Raises Speed and lowers Defense by one stage each upon being hit by a physical move.

Moves

Moves Omastar learns by level up in Sword / Shield

“Evo” means Omastar learns the move the moment it evolves: Crunch.

TM moves (41)

Omastar can learn 41 moves from TMs in Sword / Shield: Pin Missile, Hyper Beam, Giga Impact, Rest, Rock Slide, Thief, Snore, Protect, Icy Wind, Attract, Sandstorm, Rain Dance, Hail, Whirlpool, Facade, Dive, Rock Tomb, Mud Shot, Rock Blast, Brine, Round, Body Slam, Hydro Pump, Surf, Ice Beam, Blizzard, Waterfall, Substitute, Spikes, Endure, Sleep Talk, Crunch, Muddy Water, Iron Defense, Gyro Ball, Toxic Spikes, Earth Power, Stone Edge, Stealth Rock, Scald, Liquidation.

Egg moves (10), which Omanyte can hatch knowing:Aurora Beam, Bite, Bubble Beam, Haze, Knock Off, Reflect Type, Slam, Supersonic, Tickle, Water Pulse.

Move tutor moves (1): Meteor Beam.

Breeding & training

• Gender: 87.5% male, 12.5% female.
• Egg groups: Water 1, Water 3.
• Egg cycles: 30 (steps to hatch, Scarlet/Violet: 3,840).
• Catch rate: 45 out of 255.
• Base friendship (Gen 8 onward): 50.
• Growth rate: Medium (1,000,000 experience points to reach level 100).
• Defeating it gives 2 Defense effort values.
• Base experience yield: 173.

Pokédex entries

Omastar's sharp fangs could crush rock, but the Pokémon can attack only the prey that come within reach of its tentacles. (Shield)

Weighed down by a large and heavy shell, Omastar couldn't move very fast. Some say it went extinct because it was unable to catch food. (Sword)

Its sharp beak rings its mouth. Its shell was too big for it to move freely, so it became extinct. (Let’s Go, Pikachu!, Let’s Go, Eevee!)

It wraps its prey in its tentacles to immobilize them and then finishes them off with its sharp fangs. (Ultra Moon)

Its heavy shell is thought to be the reason this ancient Pokémon died out. It's apparently a distant ancestor of Octillery. (Ultra Sun)

Omastar uses its tentacles to capture its prey. It is believed to have become extinct because its shell grew too large and heavy, causing its movements to become too slow and ponderous. (Ruby, Sapphire, Omega Ruby, Alpha Sapphire)

Names around the world

Trivia

• Highest Sp. Atk among Water types in Gen 1: 115.
• Highest Sp. Atk among Rock types in Gen 1: 115.
• Taller than 47% of all Pokémon (1 m).
• Heavier than 57% of all Pokémon (35 kg).
• Base stat total 495, ranked #317 of 1,025.
• Its best stat is Defense, ranked #52 of 1,025.
• One of 11 Pokémon that are both Rock and Water.
• One of 170 blue Pokémon.
• Number 139 of 151 Pokémon introduced in Generation 1 (Kanto).
• Part of an evolution family of 2 Pokémon.
• Can learn 60 different moves in Sword / Shield.
• Catch rate 45: about 5.9% per Poké Ball at full health.
• Appears in 15 distinct Pokédex entries.

Sources and fact-checking

• Stats, types, abilities, moves, evolutions, forms and Pokédex entries: PokéAPI open game data.
• Lore: written by pokee.si in our own words, researched from Bulbapedia: Omastar (Pokémon), Serebii: Omastar (Sword/Shield Pokédex).
• Pronunciation (OM-uh-star): it follows how the English anime, games or official videos say it.

Last checked: 19 October 2026. Every sentence of the lore was checked against Bulbapedia, Serebii and the game data.

Explore

Rock-type Pokémon · Water-type Pokémon · Rock/Water weaknesses and matchups · Kanto region guide · Swift Swim ability · Shell Armor ability · Weak Armor ability · Compare Omastar · Full Pokédex · Type chart · All moves

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Gen 1 Rock-type Pokémon · Gen 1 Water-type Pokémon · Gen 1 Pokémon list · Blue Pokémon list · Water 1 egg group · Water 3 egg group · Pokémon that start with O

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