These might not be the only ways to get the items. For example, there is an NPC that gives you a light ball.
Sitrus berry - Trumbeak
Silverpowder - Butterfree, Masquerain
Light ball - Pikachu
Leftovers - Munchlax, Snorlax
King's rock - Slowbro, Slowking, Hariyama, Poliwhirl, Poliwrath, Politoed
Twistedspoon - Abra
Black sludge - Grimer, Garbodor
Black belt - Makuhita
Soft sand - Diglett, Dugtrio, Trapinch
Sharp beak - Spearow, Fearow
Hard stone - Roggenrola, Boldore
Wide lens - Sableye
Poison barb - Tentacool, Tentacruel, Mareanie
Dragon fang - Bagon, Shelgon, Salamence
Light clay - Mudbray, Mudsdale
Mystic water - Dewpider, Araquanid, Goldeen, Seaking, Castform, Lapras
Miracle seed - Fomantis
Thick club - Cubone
Grassy seed - Bounsweet
Misty seed - Comfey
Spell tag - Sangygast
Magnet - Nosepass
Silk scarf - Trubbish, Garbodor
Quick powder - Ditto
Metal powder - Ditto
Mental herb - Pancham, Pangoro
Charcoal - Torkoal, Turtonator
Electric seed - Togedemaru
Black glasses - Sandile
Chesto berry - Mimikyu
Nevermelt ice - Vanillite, Vanillish
Psychic seed - Exeggcute
Razor claw - Jangmo-o, Hakamo-o, Kommo-o
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