Weak toGhostGrassElectricDark ×1.6

Attacker	Type	Moveset	DPS
Regieleki	Electric	Lock OnThunder CageLegacy	45.0
Zeraora	Electric	Volt SwitchPlasma Fists	39.7
Kartana	GrassSteel	Razor LeafLeaf Blade	39.6
Blacephalon	FireGhost	AstonishShadow Ball	39.4
Zekrom	DragonElectric	Charge BeamFusion BoltLegacy	38.8
Xurkitree	Electric	Thunder ShockDischarge	38.4
Darkrai	Dark	SnarlShadow Ball	35.5
Chandelure	GhostFire	HexShadow Ball	35.2
Gengar	GhostPoison	LickShadow BallLegacy	35.1
Absol	Dark	SnarlBrutal SwingLegacy	34.4
Roserade	GrassPoison	Magical LeafLeaf Storm	33.8
Dragapult	DragonGhost	AstonishShadow Ball	33.6

Rainy boosts the Electric attacks above. Fog and Rainy boost Frillish.

Level 40, 15 attack IV, costed against Frillish's own defense and typing, one per evolution family.

Frillish's moveset, CP and shiny All counters Raid board

Questions people ask

What is Frillish weak to in Pokémon GO?

Frillish takes 1.6 times from Ghost, Grass, Electric and Dark.

What's the best counter to Frillish?

Regieleki with Lock On and Thunder Cage, worth 45.0 damage per second against Frillish's own defense. The full ranking is above.