Weak toGroundPsychic ×1.6

Attacker	Type	Moveset	DPS
Deoxys	Psychic	Zen HeadbuttPsycho Boost	41.1
Mewtwo	Psychic	ConfusionPsystrikeLegacy	33.5
Alakazam	Psychic	ConfusionPsychicLegacy	28.6
Groudon	Ground	Mud ShotPrecipice BladesLegacy	27.8
Azelf	Psychic	ConfusionFuturesight	27.8
Hoopa	PsychicGhost	ConfusionPsychic	27.6
Espeon	Psychic	ConfusionPsychic	27.6
Regigigas	Normal	Zen HeadbuttCrush GripLegacy	27.6
Lunala	PsychicGhost	ConfusionPsychic	27.0
Tapu Lele	PsychicFairy	ConfusionFuturesight	26.7
Latios	DragonPsychic	Zen HeadbuttPsychic	26.5
Excadrill	GroundSteel	Mud SlapEarthquake	26.4

Windy boosts the Psychic attacks above. Overcast boosts Muk.

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

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

Questions people ask

What is Muk weak to in Pokémon GO?

Muk takes 1.6 times from Ground and Psychic.

What's the best counter to Muk?

Deoxys with Zen Headbutt and Psycho Boost, worth 41.1 damage per second against Muk's own defense. The full ranking is above.