What Pokemon need a trade to evolve?

Answer 1

Generation I

• Kadabra to Alakazam
• Machoke to Machamp
• Graveler to Golem
• Haunter to Gengar

Generation II

• Poliwhirl to Politoed (when holding King's Rock)
• Slowpoke to Slowking (when holding King's Rock)
• Onix to Steelix (when holding Metal Coat)
• Seadra to Kingdra (when holdingDragon Scale)
• Scyther to Scizor (when holding Metal Coat)
• Porygon to Porygon2 (when holding Up-Grade)

Generation III

• Clamperl to Huntail (when holdingDeepSeaTooth)
• Clamperl to Gorebyss (when holdingDeepSeaScale)

Generation IV

• Rhydon to Rhyperior (when holding Protector)
• Electabuzz to Electivire (when holding Electirizer)
• Magmar to Magmortar (when holding Magmarizer)
• Porygon2 to Porygon-Z (when holding Dubious Disc)

Generation V

• Boldore to Gigalith
• Gurdurr to Conkeldurr
• Karrablast to Escavalier (if traded for Shelmet)
• Shelmet to Accelgor (if traded for Karrablast)
• Feebas to Milotic (when holding Prism Scale)