Carrion Howler

Pay 1 life: Carrion Howler gets +2/-1 until end of turn.

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.

Robaran Mercenaries

Vigilance
Robaran Mercenaries has all activated abilities of all legendary creatures you control.

Hammers of Moradin

Myriad (Whenever this creature attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)
Whenever Hammers of Moradin attacks, for each opponent, tap up to one target creature that player controls.

Genasi Enforcers

Myriad (Whenever this creature attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)
{1}{R}: Creatures you control named Genasi Enforcers get +1/+0 until end of turn.

Likeness Looter

Flying
{T}: Draw a card, then discard a card.
{X}: Likeness Looter becomes a copy of target creature card in your graveyard with mana value X, except it has flying and this ability. Activate only as a sorcery.

Wyrm's Crossing Patrol

Myriad (Whenever this creature attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)

Polygoyf

Trample, myriad (Whenever this creature attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)
Polygoyf's power is equal to the number of card types among cards in all graveyards and its toughness is equal to that number plus 1.

Auton Soldier

You may have Auton Soldier enter as a copy of any creature on the battlefield, except it isn't legendary, is an artifact in addition to its other types, and has myriad. (Whenever it attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)

Necrotic Ooze

As long as Necrotic Ooze is on the battlefield, it has all activated abilities of all creature cards in all graveyards.

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.

Scion of Calamity

Myriad (Whenever this creature attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)
Whenever Scion of Calamity deals combat damage to a player, destroy target artifact or enchantment that player controls.

Experiment Kraj

Experiment Kraj has all activated abilities of each other creature with a +1/+1 counter on it.
{T}: Put a +1/+1 counter on target creature.

Volrath's Shapeshifter

As long as the top card of your graveyard is a creature card, Volrath's Shapeshifter has the full text of that card and has the text "{2}: Discard a card." (Volrath's Shapeshifter has that card's name, mana cost, color, types, abilities, power, and toughness.)
{2}: Discard a card.

Mossbridge Troll

If Mossbridge Troll would be destroyed, regenerate it.
Tap any number of untapped creatures you control other than Mossbridge Troll with total power 10 or greater: Mossbridge Troll gets +20/+20 until end of turn.

Shameless Charlatan

Commander creatures you own have "{2}{U}: This creature becomes a copy of another target creature."

Havengul Lich

{1}: You may cast target creature card in a graveyard this turn. When you cast it this turn, Havengul Lich gains all activated abilities of that card until end of turn.

Olag, Ludevic's Hubris

As this creature transforms into Olag, Ludevic's Hubris, it becomes a copy of a creature card exiled with it, except its name is Olag, Ludevic's Hubris, it's 4/4, and it's a legendary blue and black Zombie in addition to its other colors and types. Put a number of +1/+1 counters on Olag equal to the number of creature cards exiled with it.

Ludevic, Necrogenius

Whenever Ludevic, Necrogenius enters or attacks, mill a card.
{X}{U}{U}{B}{B}, Exile X creature cards from your graveyard: Transform Ludevic. X can't be 0. Activate only as a sorcery.

Ludevic, Necrogenius // Olag, Ludevic's Hubris

Psychatog

Discard a card: Psychatog gets +1/+1 until end of turn.
Exile two cards from your graveyard: Psychatog gets +1/+1 until end of turn.

Battle Angels of Tyr

Flying, myriad
Whenever Battle Angels of Tyr deals combat damage to a player, draw a card if that player has more cards in hand than each other player. Then you create a Treasure token if that player controls more lands than each other player. Then you gain 3 life if that player has more life than each other player.

Lazav, Wearer of Faces

Whenever Lazav, Wearer of Faces attacks, exile target card from a graveyard, then investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")
Whenever you sacrifice a Clue, you may have Lazav become a copy of a creature card exiled with it until end of turn.

Quicksilver Elemental

{U}: Quicksilver Elemental gains all activated abilities of target creature until end of turn. (If any of the abilities use that creature's name, use this creature's name instead.)
You may spend blue mana as though it were mana of any color to pay the activation costs of Quicksilver Elemental's abilities.

Artisan of Forms

Heroic — Whenever you cast a spell that targets Artisan of Forms, you may have Artisan of Forms become a copy of target creature, except it has this ability.

Shapesharer

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

Legion Loyalty

Creatures you control have myriad. (Whenever a creature with myriad attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)

Lazotep Convert

You may have Lazotep Convert enter as a copy of any creature card in a graveyard, except it's a 4/4 black Zombie in addition to its other colors and types.

Invasion of Amonkhet

(As a Siege enters, choose an opponent to protect it. You and others can attack it. When it's defeated, exile it, then cast it transformed.)
When Invasion of Amonkhet enters, each player mills three cards, then each opponent discards a card and you draw a card. (To mill three cards, a player puts the top three cards of their library into their graveyard.)

Invasion of Amonkhet // Lazotep Convert

Phyrexian Devourer

When Phyrexian Devourer's power is 7 or greater, sacrifice it.
Exile the top card of your library: Put X +1/+1 counters on Phyrexian Devourer, where X is the exiled card's mana value.

Mirage Mirror

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

Scurry of Squirrels

Myriad, myriad (Whenever this creature attacks, for each opponent other than defending player, you may create a token that's a copy of this creature that's tapped and attacking that player or a planeswalker they control. Then do it again. Exile the tokens at end of combat.)
Whenever Scurry of Squirrels deals combat damage to a player, put a +1/+1 counter on target creature you control.

Chittering Dispatcher

Devoid (This card has no color.)
Myriad
When Chittering Dispatcher leaves the battlefield, create a 0/1 colorless Eldrazi Spawn creature token with "Sacrifice this creature: Add {C}."

Psychic Frog

Whenever Psychic Frog deals combat damage to a player or planeswalker, draw a card.
Discard a card: Put a +1/+1 counter on Psychic Frog.
Exile three cards from your graveyard: Psychic Frog gains flying until end of turn.

Patchwork Crawler

{2}{U}: Exile target creature card from your graveyard and put a +1/+1 counter on Patchwork Crawler.
Patchwork Crawler has all activated abilities of all creature cards exiled with it.

Case of the Shifting Visage

At the beginning of your upkeep, surveil 1.
To solve — There are fifteen or more cards in your graveyard. (If unsolved, solve at the beginning of your end step.)
Solved — Whenever you cast a nonlegendary creature spell, copy that spell. (The copy becomes a token.)

Wizards of Thay

Myriad (Whenever this creature attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)
Instant and sorcery spells you cast cost {1} less to cast.
You may cast sorcery spells as though they had flash.

Blade of Selves

Equipped creature has myriad. (Whenever it attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)
Equip {4}

Dalek Squadron

Menace
Myriad (Whenever this creature attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)

Bloodtracker

Flying
{B}, Pay 2 life: Put a +1/+1 counter on Bloodtracker.
When Bloodtracker leaves the battlefield, draw a card for each +1/+1 counter on it.

Myr Welder

Imprint — {T}: Exile target artifact card from a graveyard.
Myr Welder has all activated abilities of all cards exiled with it.

Wall of Blood

Defender (This creature can't attack.)
Pay 1 life: Wall of Blood gets +1/+1 until end of turn.

Souldrinker

Pay 3 life: Put a +1/+1 counter on Souldrinker.

Sumala Rumblers

Sumala Rumblers's power is equal to the number of creatures you control.
Myriad (Whenever this creature attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)

Curie, Emergent Intelligence

Whenever Curie, Emergent Intelligence deals combat damage to a player, draw cards equal to its base power.
{1}{U}, Exile another nontoken artifact creature you control: Curie becomes a copy of the exiled creature, except it has "Whenever this creature deals combat damage to a player, draw cards equal to its base power."

Crystalline Resonance

Whenever you cycle a card, you may have Crystalline Resonance become a copy of another target permanent until your next turn, except it has this ability.

Shifting Woodland

Shifting Woodland enters tapped unless you control a Forest.
{T}: Add {G}.
Delirium — {2}{G}{G}: Shifting Woodland becomes a copy of target permanent card in your graveyard until end of turn. Activate only if there are four or more card types among cards in your graveyard.

Blade of Shared Souls

For Mirrodin! (When this Equipment enters, create a 2/2 red Rebel creature token, then attach this to it.)
Whenever Blade of Shared Souls becomes attached to a creature, for as long as Blade of Shared Souls remains attached to it, you may have that creature become a copy of another target creature you control.
Equip {2}

Elturel Survivors

Trample, myriad (Whenever this creature attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)
As long as Elturel Survivors is attacking, it gets +X/+0, where X is the number of lands defending player controls.

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.

Mairsil, the Pretender

When Mairsil, the Pretender enters, you may exile an artifact or creature card from your hand or graveyard and put a cage counter on it.
Mairsil, the Pretender has all activated abilities of all cards you own in exile with cage counters on them. You may activate each of those abilities only once each turn.