18 cards where the text includes “a copy of any creature” and the card types include “shapeshifter”

Activated Sleeper (Dominaria United Commander #24)
Altered Ego (Shadows over Innistrad #241)
Body Double (Commander Masters #75)
Callidus Assassin (Warhammer 40,000 Commander #109)
Clone (Magic 2014 #47)
Dack's Duplicate (Double Masters 2022 #198)
Evil Twin (Battlebond #222)
Flesh Duplicate (Doctor Who #44)
Gigantoplasm (Commander 2015 #11)
Pirated Copy (Jumpstart 2022 #16)
Progenitor Mimic (Double Masters #212)
Protean Raider (Rivals of Ixalan #167)
Quicksilver Gargantuan (Scars of Mirrodin #39)
Stunt Double (Ravnica: Clue Edition #101)
Undercover Operative (Streets of New Capenna #63)
Vesuvan Doppelganger (Masters Edition #54)
Vizier of Many Faces (Murders at Karlov Manor Commander #123)
Wall of Stolen Identity (Commander 2019 #13)

Though this query has ended, its relics still slumber in New Argive.