Hex is learned by 45 species by level, 116 by machine and 5 by egg

Effect, in PokéAPI's words

“Has double power if the target has a major status ailment.”

Who learns it

117 species in all, 8 of 10 games shown

Scarlet and Violet: 94 species

Species	Method	Level
Froslass	Level up, Machine	Evolve
Chandelure	Level up, Machine	1
Spectrier	Level up, Machine	12
Drifloon	Level up, Machine	16
Drifblim	Level up, Machine	16
Litwick	Level up, Machine	16
Lampent	Level up, Machine	16
Drakloak	Level up, Machine	18
Dragapult	Level up, Machine	18
Phantump	Level up, Machine	20
Trevenant	Level up, Machine	20
Giratina	Level up, Machine	21
Bramblin	Level up, Machine	21
Brambleghast	Level up, Machine	21
Shuppet	Level up, Machine	22
Banette	Level up, Machine	22
Misdreavus	Level up, Machine	23
Gastly	Level up, Machine	24
Haunter	Level up, Machine	24
Gengar	Level up, Machine	24
Spiritomb	Level up, Machine	25
Tentacool	Level up, Machine	28
Tentacruel	Level up, Machine	28
Toedscool	Level up, Machine	28
Toedscruel	Level up, Machine	28
Poltchageist	Level up, Machine	30
Sinistcha	Level up, Machine	30
Duskull	Level up, Machine	32
Dusclops	Level up, Machine	32
Dusknoir	Level up, Machine	32
Rotom	Level up, Machine	35
Skeledirge	Level up, Machine	47
Vulpix	Machine
Ninetales	Machine
Grimer	Machine
Muk	Machine
Hypno	Machine
Mewtwo	Machine
Mew	Machine
Typhlosion	Machine
Spinarak	Machine
Ariados	Machine
Murkrow	Machine
Dunsparce	Machine
Qwilfish	Machine
Shiftry	Machine
Sableye	Machine
Snorunt	Machine
Glalie	Machine
Vespiquen	Machine
Mismagius	Machine
Honchkrow	Machine
Stunky	Machine
Skuntank	Machine
Bronzor	Machine
Bronzong	Machine
Gallade	Machine
Darkrai	Machine
Arceus	Machine
Zorua	Machine
Zoroark	Machine
Amoonguss	Machine
Eelektross	Machine
Golett	Machine
Golurk	Machine
Delphox	Machine
Decidueye	Machine
Toxapex	Machine
Sandygast	Machine
Palossand	Machine
Mimikyu	Machine
Lunala	Machine
Toxtricity	Machine
Sinistea	Machine
Polteageist	Machine
Pincurchin	Machine
Basculegion	Machine
Ceruledge	Machine
Espathra	Machine
Greavard	Machine
Houndstone	Machine
Dudunsparce	Machine
Brute Bonnet	Machine
Flutter Mane	Machine
Gimmighoul	Machine
Gholdengo	Machine
Wo-Chien	Machine
Chien-Pao	Machine
Ting-Lu	Machine
Chi-Yu	Machine
Iron Valiant	Machine
Munkidori	Machine
Fezandipiti	Machine
Pecharunt	Machine

Legends Arceus: 21 species

Species	Method	Level
Gastly	Level up	11
Haunter	Level up	11
Gengar	Level up	11
Duskull	Level up	11
Dusclops	Level up	11
Spiritomb	Level up	11
Dusknoir	Level up	11
Rotom	Level up	11
Basculegion	Level up	11
Darkrai	Level up	12
Tentacool	Level up	18
Tentacruel	Level up	18
Misdreavus	Level up	18
Mismagius	Level up	18
Bronzor	Level up	18
Bronzong	Level up	18
Froslass	Level up	18
Vulpix	Level up	21
Ninetales	Level up	21
Drifloon	Level up	21
Drifblim	Level up	21

Brilliant Diamond and Shining Pearl: 23 species

Species	Method	Level
Froslass	Level up	Evolve, 1
Mismagius	Level up	1
Drifloon	Level up	16
Drifblim	Level up	16
Giratina	Level up	21
Shuppet	Level up	22
Banette	Level up	22
Misdreavus	Level up	23
Gastly	Level up	24
Haunter	Level up	24
Gengar	Level up	24
Spiritomb	Level up	25
Tentacool	Level up	28
Tentacruel	Level up	28
Duskull	Level up	32
Dusclops	Level up	32
Dusknoir	Level up	32
Rotom	Level up	35
Vulpix	Egg
Dunsparce	Egg
Castform	Egg
Absol	Egg
Snorunt	Egg

Sword and Shield: 68 species

Species	Method	Level
Froslass	Level up, Machine	Evolve, 1
Chandelure	Level up, Machine	1
Spectrier	Level up, Machine	12
Drifloon	Level up, Machine	16
Drifblim	Level up, Machine	16
Litwick	Level up, Machine	16
Lampent	Level up, Machine	16
Drakloak	Level up, Machine	18
Dragapult	Level up, Machine	18
Frillish	Level up, Machine	20
Jellicent	Level up, Machine	20
Phantump	Level up, Machine	20
Trevenant	Level up, Machine	20
Giratina	Level up, Machine	21
Gastly	Level up, Machine	24
Haunter	Level up, Machine	24
Gengar	Level up, Machine	24
Yamask	Level up, Machine	24
Cofagrigus	Level up, Machine	24
Runerigus	Level up, Machine	24
Spiritomb	Level up, Machine	25
Cursola	Level up, Machine	25
Tentacool	Level up, Machine	28
Tentacruel	Level up, Machine	28
Duskull	Level up, Machine	32
Dusclops	Level up, Machine	32
Dusknoir	Level up, Machine	32
Rotom	Level up, Machine	35
Nidoqueen	Machine
Nidoking	Machine
Vulpix	Machine
Ninetales	Machine
Mew	Machine
Crobat	Machine
Dunsparce	Machine
Qwilfish	Machine
Shedinja	Machine
Sableye	Machine
Baltoy	Machine
Claydol	Machine
Absol	Machine
Snorunt	Machine
Glalie	Machine
Vespiquen	Machine
Stunky	Machine
Skuntank	Machine
Bronzor	Machine
Bronzong	Machine
Venipede	Machine
Whirlipede	Machine
Scolipede	Machine
Zorua	Machine
Zoroark	Machine
Amoonguss	Machine
Pumpkaboo	Machine
Gourgeist	Machine
Decidueye	Machine
Toxapex	Machine
Mimikyu	Machine
Dhelmise	Machine
Lunala	Machine
Nihilego	Machine
Marshadow	Machine
Naganadel	Machine
Toxtricity	Machine
Sinistea	Machine
Polteageist	Machine
Pincurchin	Machine

Ultra Sun and Ultra Moon: 27 species

Species	Method	Level
Chandelure	Level up	1
Yamask	Level up	17
Cofagrigus	Level up	17
Shuppet	Level up	22
Banette	Level up	22
Misdreavus	Level up	23
Vulpix	Level up, Egg	26
Drifloon	Level up	27
Drifblim	Level up	27
Litwick	Level up	28
Lampent	Level up	28
Duskull	Level up	38
Tentacool	Level up	40
Dusclops	Level up	40
Dusknoir	Level up	40
Gastly	Level up	43
Frillish	Level up	43
Tentacruel	Level up	44
Jellicent	Level up	45
Rotom	Level up	50
Giratina	Level up	50
Haunter	Level up	55
Gengar	Level up	55
Dunsparce	Egg
Castform	Egg
Absol	Egg
Snorunt	Egg

Sun and Moon: 27 species

Species	Method	Level
Chandelure	Level up	1
Yamask	Level up	17
Cofagrigus	Level up	17
Shuppet	Level up	22
Banette	Level up	22
Misdreavus	Level up	23
Vulpix	Level up, Egg	26
Drifloon	Level up	27
Drifblim	Level up	27
Litwick	Level up	28
Lampent	Level up	28
Duskull	Level up	38
Tentacool	Level up	40
Dusclops	Level up	40
Dusknoir	Level up	40
Gastly	Level up	43
Frillish	Level up	43
Tentacruel	Level up	44
Jellicent	Level up	45
Rotom	Level up	50
Giratina	Level up	50
Haunter	Level up	55
Gengar	Level up	55
Dunsparce	Egg
Castform	Egg
Absol	Egg
Snorunt	Egg

Omega Ruby and Alpha Sapphire: 27 species

Species	Method	Level
Chandelure	Level up	1
Yamask	Level up	17
Cofagrigus	Level up	17
Shuppet	Level up	22
Banette	Level up	22
Misdreavus	Level up	23
Vulpix	Level up, Egg	26
Drifloon	Level up	27
Drifblim	Level up	27
Litwick	Level up	28
Lampent	Level up	28
Duskull	Level up	38
Tentacool	Level up	40
Dusclops	Level up	40
Dusknoir	Level up	40
Gastly	Level up	43
Frillish	Level up	43
Tentacruel	Level up	44
Jellicent	Level up	45
Rotom	Level up	50
Giratina	Level up	50
Haunter	Level up	55
Gengar	Level up	55
Dunsparce	Egg
Castform	Egg
Absol	Egg
Snorunt	Egg

X and Y: 27 species

Species	Method	Level
Chandelure	Level up	1
Yamask	Level up	17
Cofagrigus	Level up	17
Misdreavus	Level up	23
Shuppet	Level up	26
Banette	Level up	26
Drifloon	Level up	27
Drifblim	Level up	27
Vulpix	Level up, Egg	28
Litwick	Level up	28
Lampent	Level up	28
Duskull	Level up	38
Dusclops	Level up	42
Dusknoir	Level up	42
Tentacool	Level up	43
Gastly	Level up	43
Frillish	Level up	43
Jellicent	Level up	45
Tentacruel	Level up	47
Rotom	Level up	50
Giratina	Level up	50
Haunter	Level up	55
Gengar	Level up	55
Dunsparce	Egg
Castform	Egg
Absol	Egg
Snorunt	Egg

Changed over time

One change since Generation V

1. Through Gen VPower 5065 from X and Y, Generation VI