Omastar's Weaknesses

Best Counters

Omastar is especially weak against Grass type Pokemon, they will deal 4x damage to it!

The types that are strong against Omastar are Grass, Electric, Fighting type Pokemon.

Ground types will also deal super-effective damage against Omastar, but be careful using Pokemon of this type because they may also receive extra damage from some of Omastar's attacks!

Weaknesses

Omastar's type is Rock and Water.

Omastar is especially vulnerable to Grass attacks, it will receive a super effective four times (4x) the amount of damage! Since Grass type Pokemon are especially strong against Omastar, you should attack with this type of Pokemon.

Omastar has a weakness to Grass, Electric, Fighting, Ground types. These Pokemon types will be strong against Omastar, causing Omastar to take a super effective quadruple (4x) damage from Grass type attacks, and causing Omastar to take a super effective double (2x) damage from Electric, Fighting, Ground type attacks.

Please keep in mind that Omastar is resistant to attacks from Bug, Flying, Ice, Normal, Poison, Fire types, and these attacks are not very effective and cause reduced damage, so they should be avoided.