Which Pokemon evolve by trading?

Kadabra --> Alakazam

Machoke --> Machamp

Graveller --> Golem

Haunter --> Gengar

Seadra (Dragon Scale) --> Kingdra

Poliwhirl (King's Rock) --> Politoed

Slowpoke (King's Rock) --> Slowking

Onix (Metal Coat) --> Steelix

Rhydon (Protector) --> Rhypieror

Syther (Metal Coat) --> Scizor

Electabuzz (Electirizer) --> Electivire

Magmar (Magmarizer) --> Magmortar

Porygon (Upgrade) --> Porygon 2

Porygon 2 (Dubious Disc) --> Porygon-Z

Duskull (Reaper Cloth) --> Dusknoir

Clamperl (Deepsea Tooth) --> Huntail

Clamperl (Deepsea Scale) --> Gorebyss