Scale Shot is learned by 62 species by machine, 63 by tutor and 1 by egg

Effect, in PokéAPI's words

“Boosts the user’s Speed and lowers their Defense by one stage after inflicting damage two to five times in a row.”

Who learns it

81 species in all, 2 games

Scarlet and Violet: 62 species

Species	Method	Level
Ekans	Machine
Arbok	Machine
Horsea	Machine
Seadra	Machine
Gyarados	Machine
Dratini	Machine
Dragonair	Machine
Dragonite	Machine
Mew	Machine
Feraligatr	Machine
Dunsparce	Machine
Gligar	Machine
Qwilfish	Machine
Kingdra	Machine
Lugia	Machine
Sceptile	Machine
Flygon	Machine
Feebas	Machine
Milotic	Machine
Luvdisc	Machine
Latias	Machine
Latios	Machine
Rayquaza	Machine
Gible	Machine
Gabite	Machine
Garchomp	Machine
Gliscor	Machine
Dialga	Machine
Palkia	Machine
Serperior	Machine
Basculin	Machine
Krokorok	Machine
Krookodile	Machine
Alomomola	Machine
Axew	Machine
Fraxure	Machine
Haxorus	Machine
Hydreigon	Machine
Reshiram	Machine
Zekrom	Machine
Kyurem	Machine
Skrelp	Machine
Dragalge	Machine
Salandit	Machine
Salazzle	Machine
Jangmo-o	Machine
Hakamo-o	Machine
Kommo-o	Machine
Silicobra	Machine
Sandaconda	Machine
Arrokuda	Machine
Barraskewda	Machine
Regidrago	Machine
Basculegion	Machine
Overqwil	Machine
Cyclizar	Machine
Veluza	Machine
Dudunsparce	Machine
Baxcalibur	Machine
Roaring Moon	Machine, Egg
Koraidon	Machine
Gouging Fire	Machine

Sword and Shield: 63 species

Species	Method	Level
Charizard	Tutor
Horsea	Tutor
Seadra	Tutor
Goldeen	Tutor
Seaking	Tutor
Gyarados	Tutor
Dratini	Tutor
Dragonair	Tutor
Dragonite	Tutor
Mew	Tutor
Dunsparce	Tutor
Qwilfish	Tutor
Kingdra	Tutor
Lugia	Tutor
Sceptile	Tutor
Carvanha	Tutor
Sharpedo	Tutor
Flygon	Tutor
Feebas	Tutor
Milotic	Tutor
Relicanth	Tutor
Latias	Tutor
Latios	Tutor
Rayquaza	Tutor
Gible	Tutor
Gabite	Tutor
Garchomp	Tutor
Dialga	Tutor
Palkia	Tutor
Basculin	Tutor
Krookodile	Tutor
Axew	Tutor
Fraxure	Tutor
Haxorus	Tutor
Druddigon	Tutor
Hydreigon	Tutor
Reshiram	Tutor
Zekrom	Tutor
Kyurem	Tutor
Skrelp	Tutor
Dragalge	Tutor
Helioptile	Tutor
Heliolisk	Tutor
Tyrunt	Tutor
Tyrantrum	Tutor
Zygarde	Tutor
Wishiwashi	Tutor
Salandit	Tutor
Salazzle	Tutor
Turtonator	Tutor
Drampa	Tutor
Jangmo-o	Tutor
Hakamo-o	Tutor
Kommo-o	Tutor
Naganadel	Tutor
Inteleon	Tutor
Chewtle	Tutor
Drednaw	Tutor
Silicobra	Tutor
Sandaconda	Tutor
Arrokuda	Tutor
Barraskewda	Tutor
Regidrago	Tutor