Avalanche is learned by 14 species by level, 95 by machine and 8 by egg

Effect, in PokéAPI's words

“Inflicts double damage if the user takes damage before attacking this turn.”

Who learns it

95 species in all, 8 of 12 games shown

Scarlet and Violet: 73 species

Species	Method	Level
Glastrier	Level up, Machine	12
Bergmite	Level up, Machine	18
Avalugg	Level up, Machine	18
Cetoddle	Level up, Machine	27
Cetitan	Level up, Machine	27
Crabominable	Level up, Machine	29
Blastoise	Machine
Slowpoke	Machine
Slowbro	Machine
Seel	Machine
Dewgong	Machine
Shellder	Machine
Cloyster	Machine
Rhydon	Machine
Gyarados	Machine
Lapras	Machine
Articuno	Machine
Mewtwo	Machine
Mew	Machine
Feraligatr	Machine
Wooper	Machine
Quagsire	Machine
Slowking	Machine
Sneasel	Machine
Teddiursa	Machine
Ursaring	Machine
Swinub	Machine
Piloswine	Machine
Delibird	Machine
Blissey	Machine
Suicune	Machine
Tyranitar	Machine
Lugia	Machine
Mudkip	Machine
Marshtomp	Machine
Swampert	Machine
Crawdaunt	Machine
Milotic	Machine
Snorunt	Machine
Glalie	Machine
Regice	Machine
Kyogre	Machine
Rayquaza	Machine
Empoleon	Machine
Rampardos	Machine
Bastiodon	Machine
Snover	Machine
Abomasnow	Machine
Weavile	Machine
Rhyperior	Machine
Glaceon	Machine
Mamoswine	Machine
Froslass	Machine
Palkia	Machine
Regigigas	Machine
Arceus	Machine
Oshawott	Machine
Dewott	Machine
Samurott	Machine
Cubchoo	Machine
Beartic	Machine
Cryogonal	Machine
Kyurem	Machine
Frosmoth	Machine
Eiscue	Machine
Ursaluna	Machine
Garganacl	Machine
Dondozo	Machine
Iron Bundle	Machine
Frigibax	Machine
Arctibax	Machine
Baxcalibur	Machine
Chien-Pao	Machine

Brilliant Diamond and Shining Pearl: 57 species

Species	Method	Level
Blastoise	Machine
Nidoqueen	Machine
Nidoking	Machine
Slowbro	Machine
Dewgong	Machine
Shellder	Machine
Cloyster	Machine
Rhydon	Machine
Kangaskhan	Machine
Starmie	Machine
Jynx	Machine
Gyarados	Machine
Lapras	Machine
Articuno	Machine
Mewtwo	Machine
Mew	Machine
Feraligatr	Machine
Slowking	Machine
Sneasel	Machine
Ursaring	Machine
Swinub	Machine
Piloswine	Machine
Delibird	Machine
Smoochum	Machine
Blissey	Machine
Suicune	Machine
Tyranitar	Machine
Lugia	Machine
Mudkip	Machine
Marshtomp	Machine
Swampert	Machine
Exploud	Machine
Aggron	Machine
Sharpedo	Machine
Wailmer	Machine
Wailord	Machine
Crawdaunt	Machine
Milotic	Machine
Castform	Machine
Snorunt	Machine
Glalie	Machine
Walrein	Machine
Regice	Machine
Kyogre	Machine
Rayquaza	Machine
Empoleon	Machine
Rampardos	Machine
Bastiodon	Machine
Snover	Machine
Abomasnow	Machine
Weavile	Machine
Rhyperior	Machine
Glaceon	Machine
Mamoswine	Machine
Froslass	Machine
Palkia	Machine
Regigigas	Machine

Sword and Shield: 66 species

Species	Method	Level
Glastrier	Level up, Machine	12
Vanillite	Level up, Machine	16
Vanillish	Level up, Machine	16
Vanilluxe	Level up, Machine	16
Bergmite	Level up, Machine	18
Avalugg	Level up, Machine	18
Arctozolt	Level up, Machine	35
Blastoise	Machine
Nidoqueen	Machine
Nidoking	Machine
Slowbro	Machine
Shellder	Machine
Cloyster	Machine
Rhydon	Machine
Kangaskhan	Machine
Starmie	Machine
Jynx	Machine
Gyarados	Machine
Lapras	Machine
Articuno	Machine
Mewtwo	Machine
Mew	Machine
Slowking	Machine
Sneasel	Machine
Swinub	Machine
Piloswine	Machine
Delibird	Machine
Smoochum	Machine
Blissey	Machine
Suicune	Machine
Tyranitar	Machine
Lugia	Machine
Mudkip	Machine
Marshtomp	Machine
Swampert	Machine
Exploud	Machine
Aggron	Machine
Sharpedo	Machine
Wailmer	Machine
Wailord	Machine
Crawdaunt	Machine
Milotic	Machine
Snorunt	Machine
Glalie	Machine
Walrein	Machine
Regice	Machine
Kyogre	Machine
Rayquaza	Machine
Snover	Machine
Abomasnow	Machine
Weavile	Machine
Rhyperior	Machine
Glaceon	Machine
Mamoswine	Machine
Froslass	Machine
Palkia	Machine
Regigigas	Machine
Cubchoo	Machine
Beartic	Machine
Cryogonal	Machine
Amaura	Machine
Aurorus	Machine
Mr. Rime	Machine
Frosmoth	Machine
Eiscue	Machine
Arctovish	Machine

Ultra Sun and Ultra Moon: 18 species

Species	Method	Level
Vanillite	Level up	19
Vanillish	Level up	19
Vanilluxe	Level up	19
Crabominable	Level up	29
Amaura	Level up	34
Aurorus	Level up	34
Smoochum	Level up	35
Jynx	Level up	39
Bergmite	Level up	39
Avalugg	Level up	42
Shellder	Egg
Lapras	Egg
Sneasel	Egg
Swinub	Egg
Mudkip	Egg
Snorunt	Egg
Snover	Egg
Cubchoo	Egg

Sun and Moon: 18 species

Species	Method	Level
Vanillite	Level up	19
Vanillish	Level up	19
Vanilluxe	Level up	19
Crabominable	Level up	29
Amaura	Level up	34
Aurorus	Level up	34
Smoochum	Level up	35
Jynx	Level up	39
Bergmite	Level up	39
Avalugg	Level up	42
Shellder	Egg
Lapras	Egg
Sneasel	Egg
Swinub	Egg
Mudkip	Egg
Snorunt	Egg
Snover	Egg
Cubchoo	Egg

Omega Ruby and Alpha Sapphire: 17 species

Species	Method	Level
Vanillite	Level up	19
Vanillish	Level up	19
Vanilluxe	Level up	19
Amaura	Level up	34
Aurorus	Level up	34
Smoochum	Level up	35
Jynx	Level up	39
Bergmite	Level up	39
Avalugg	Level up	42
Shellder	Egg
Lapras	Egg
Sneasel	Egg
Swinub	Egg
Mudkip	Egg
Snorunt	Egg
Snover	Egg
Cubchoo	Egg

X and Y: 17 species

Species	Method	Level
Vanillite	Level up	19
Vanillish	Level up	19
Vanilluxe	Level up	19
Amaura	Level up	34
Aurorus	Level up	34
Smoochum	Level up	35
Jynx	Level up	39
Bergmite	Level up	39
Avalugg	Level up	42
Shellder	Egg
Lapras	Egg
Sneasel	Egg
Swinub	Egg
Mudkip	Egg
Snorunt	Egg
Snover	Egg
Cubchoo	Egg

Black 2 and White 2: 13 species

Species	Method	Level
Vanillite	Level up	19
Vanillish	Level up	19
Vanilluxe	Level up	19
Smoochum	Level up	35
Jynx	Level up	39
Shellder	Egg
Lapras	Egg
Sneasel	Egg
Swinub	Egg
Mudkip	Egg
Snorunt	Egg
Snover	Egg
Cubchoo	Egg