Grudge is learned by 10 species by level and 8 by egg

Effect, in PokéAPI's words

“If the user faints this turn, the PP of the move that fainted it drops to 0.”

Who learns it

18 species in all, 8 of 16 games shown

Brilliant Diamond and Shining Pearl: 12 species

Species	Method	Level
Ninetales	Level up	1
Shedinja	Level up	1
Mismagius	Level up	1
Shuppet	Level up	46
Misdreavus	Level up	50
Vulpix	Level up	52
Banette	Level up	52
Gastly	Egg
Koffing	Egg
Ralts	Egg
Duskull	Egg
Spiritomb	Egg

Sword and Shield: 14 species

Species	Method	Level
Ninetales	Level up	1
Shedinja	Level up	1
Yamask	Level up	32
Cofagrigus	Level up	32
Cursola	Level up	50
Vulpix	Level up	52
Gastly	Egg
Koffing	Egg
Ralts	Egg
Duskull	Egg
Spiritomb	Egg
Phantump	Egg
Mimikyu	Egg
Dreepy	Egg

Ultra Sun and Ultra Moon: 14 species

Species	Method	Level
Shedinja	Level up	37
Yamask	Level up	41
Vulpix	Level up	44
Cofagrigus	Level up	45
Shuppet	Level up	46
Misdreavus	Level up	50
Banette	Level up	52
Gastly	Egg
Koffing	Egg
Ralts	Egg
Duskull	Egg
Spiritomb	Egg
Phantump	Egg
Mimikyu	Egg

Sun and Moon: 14 species

Species	Method	Level
Shedinja	Level up	37
Yamask	Level up	41
Vulpix	Level up	44
Cofagrigus	Level up	45
Shuppet	Level up	46
Misdreavus	Level up	50
Banette	Level up	52
Gastly	Egg
Koffing	Egg
Ralts	Egg
Duskull	Egg
Spiritomb	Egg
Phantump	Egg
Mimikyu	Egg

Omega Ruby and Alpha Sapphire: 13 species

Species	Method	Level
Shedinja	Level up	37
Yamask	Level up	41
Vulpix	Level up	44
Cofagrigus	Level up	45
Shuppet	Level up	46
Misdreavus	Level up	50
Banette	Level up	52
Gastly	Egg
Koffing	Egg
Ralts	Egg
Duskull	Egg
Spiritomb	Egg
Phantump	Egg

X and Y: 13 species

Species	Method	Level
Yamask	Level up	41
Shedinja	Level up	43
Vulpix	Level up	44
Cofagrigus	Level up	45
Shuppet	Level up	46
Misdreavus	Level up	50
Banette	Level up	52
Gastly	Egg
Koffing	Egg
Ralts	Egg
Duskull	Egg
Spiritomb	Egg
Phantump	Egg

Black 2 and White 2: 12 species

Species	Method	Level
Yamask	Level up	41
Vulpix	Level up	44
Shedinja	Level up	45
Cofagrigus	Level up	45
Shuppet	Level up	46
Misdreavus	Level up	50
Banette	Level up	52
Gastly	Egg
Koffing	Egg
Ralts	Egg
Duskull	Egg
Spiritomb	Egg

Black and White: 12 species

Species	Method	Level
Yamask	Level up	41
Shedinja	Level up	45
Cofagrigus	Level up	45
Vulpix	Level up	47
Misdreavus	Level up	50
Shuppet	Level up	50
Banette	Level up	66
Gastly	Egg
Koffing	Egg
Ralts	Egg
Duskull	Egg
Spiritomb	Egg