Shapesharer

Changeling (This card is every creature type.)
{2}{U}: Target Shapeshifter becomes a copy of target creature until your next turn.

Phyrexian Metamorph

({U/P} can be paid with either {U} or 2 life.)
You may have Phyrexian Metamorph enter as a copy of any artifact or creature on the battlefield, except it's an artifact in addition to its other types.

Talisman of Dominance

{T}: Add {C}.
{T}: Add {U} or {B}. Talisman of Dominance deals 1 damage to you.

Mimic Vat

Imprint — Whenever a nontoken creature dies, you may exile that card. If you do, return each other card exiled with Mimic Vat to its owner's graveyard.
{3}, {T}: Create a token that's a copy of a card exiled with Mimic Vat. It gains haste. Exile it at the beginning of the next end step.

Gigantoplasm

You may have Gigantoplasm enter as a copy of any creature on the battlefield, except it has "{X}: This creature has base power and toughness X/X."

Sol Ring

Sculpting Steel

You may have Sculpting Steel enter as a copy of any artifact on the battlefield.

Mercurial Pretender

You may have Mercurial Pretender enter as a copy of a creature you control, except it has "{2}{U}{U}: Return this creature to its owner's hand."

Stunt Double

Flash
You may have Stunt Double enter as a copy of any creature on the battlefield.

Evil Twin

You may have Evil Twin enter as a copy of any creature on the battlefield, except it has "{U}{B}, {T}: Destroy target creature with the same name as this creature."

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Copy Enchantment

You may have Copy Enchantment enter as a copy of any enchantment on the battlefield.

Cemetery Puca

Whenever a creature dies, you may pay {1}. If you do, Cemetery Puca becomes a copy of that creature, except it has this ability.

Mirror Mockery

Enchant creature
Whenever enchanted creature attacks, you may create a token that's a copy of that creature. Exile that token at end of combat.

Shapeshifter's Marrow

At the beginning of each opponent's upkeep, that player reveals the top card of their library. If it's a creature card, the player puts the card into their graveyard and Shapeshifter's Marrow becomes a copy of that card. (If it does, it loses this ability.)

Mirage Mirror

{2}: Mirage Mirror becomes a copy of target artifact, creature, enchantment, or land until end of turn.

Star Compass

Star Compass enters tapped.
{T}: Add one mana of any color that a basic land you control could produce.

Dimir Doppelganger

{1}{U}{B}: Exile target creature card from a graveyard. Dimir Doppelganger becomes a copy of that card, except it has this ability.

Clever Impersonator

You may have Clever Impersonator enter as a copy of any nonland permanent on the battlefield.

Lazav, the Multifarious

When Lazav, the Multifarious enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
{X}: Lazav, the Multifarious becomes a copy of target creature card in your graveyard with mana value X, except its name is Lazav, the Multifarious, it's legendary in addition to its other types, and it has this ability.

Vizier of Many Faces

You may have Vizier of Many Faces enter as a copy of any creature on the battlefield, except if Vizier of Many Faces was embalmed, the token has no mana cost, it's white, and it's a Zombie in addition to its other types.
Embalm {3}{U}{U}

Cairn Wanderer

Changeling (This card is every creature type.)
As long as a creature card with flying is in a graveyard, Cairn Wanderer has flying. The same is true for fear, first strike, double strike, deathtouch, haste, landwalk, lifelink, protection, reach, trample, shroud, and vigilance.

Clone

You may have Clone enter as a copy of any creature on the battlefield.

Fellwar Stone

{T}: Add one mana of any color that a land an opponent controls could produce.

Dimir Signet

Identity Thief

Whenever Identity Thief attacks, you may exile another target nontoken creature. If you do, Identity Thief becomes a copy of that creature until end of turn. Return the exiled card to the battlefield under its owner's control at the beginning of the next end step.

Vesuvan Shapeshifter

As Vesuvan Shapeshifter enters or is turned face up, you may choose another creature on the battlefield. If you do, until Vesuvan Shapeshifter is turned face down, it becomes a copy of that creature, except it has "At the beginning of your upkeep, you may turn this creature face down."
Morph {1}{U}

Body Double

You may have Body Double enter as a copy of any creature card in a graveyard.

Lazav, Dimir Mastermind

Hexproof
Whenever a creature card is put into an opponent's graveyard from anywhere, you may have Lazav, Dimir Mastermind become a copy of that card, except its name is Lazav, Dimir Mastermind, it's legendary in addition to its other types, and it has hexproof and this ability.

Metamorphic Alteration

Enchant creature
As Metamorphic Alteration enters, choose a creature.
Enchanted creature is a copy of the chosen creature.

Cryptoplasm

At the beginning of your upkeep, you may have Cryptoplasm become a copy of another target creature, except it has this ability.