Menace (This creature can't be blocked except by two or more creatures.)

When Underdark Explorer enters the battlefield, you take the initiative.

Undergrowth Scavenger enters the battlefield with a number of +1/+1 counters on it equal to the number of creature cards in all graveyards.

If you would draw a card, instead look at the top three cards of your library, then put one into your hand and the rest into your graveyard.

Pay 4 life: Underrealm Lich gains indestructible until end of turn. Tap it.

, , Discard a card: Return target creature card from your graveyard to your hand.

Underworld Charger can't block.

Escape—, Exile three other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)

Underworld Charger escapes with two +1/+1 counters on it.

When Underworld Hermit enters the battlefield, create a number of 1/1 green Squirrel creature tokens equal to your devotion to black. (Each in the mana costs of permanents you control counts toward your devotion to black.)

Whenever Underworld Sentinel attacks, exile target creature card from your graveyard.

When Underworld Sentinel dies, put all cards exiled with it onto the battlefield.

Flying

Sphinx spells you cast cost less to cast.

Whenever Unesh, Criosphinx Sovereign or another Sphinx enters the battlefield under your control, reveal the top four cards of your library. An opponent separates those cards into two piles. Put one pile into your hand and the other into your graveyard.

Unhallowed Cathar can't block.

At the beginning of your end step, you lose 1 life.

Unimpeded Trespasser can't be blocked.

Changeling (This card is every creature type.)

When Unlucky Witness dies, exile the top two cards of your library. Until your next end step, you may play one of those cards.

Defender

: Unruly Catapult deals 1 damage to each opponent.

Whenever you cast an instant or sorcery spell, untap Unruly Catapult.

Whenever another creature you control dies, put a +1/+1 counter on Unruly Mob.

When Unscrupulous Contractor enters the battlefield, you may sacrifice a creature. When you do, target player draws two cards and loses 2 life.

Plot (You may pay and exile this card from your hand. Cast it as a sorcery on a later turn without paying its mana cost. Plot only as a sorcery.)

Changeling (This card is every creature type.)

Whenever you or a permanent you control becomes the target of a spell or ability an opponent controls, counter that spell or ability unless its controller pays .

Morph (You may cast this card face down as a 2/2 creature for . Turn it face up any time for its morph cost.)

When Unstable Hulk is turned face up, it gets +6/+6 and gains trample until end of turn. You skip your next turn.

Trample

Champion a Treefolk or Warrior (When this enters the battlefield, sacrifice it unless you exile another Treefolk or Warrior you control. When this leaves the battlefield, that card returns to the battlefield.)

Whenever a creature you control becomes blocked, it gets +0/+5 until end of turn.

Kicker (You may pay an additional as you cast this spell.)

Vigilance, trample

If Untamed Kavu was kicked, it enters the battlefield with three +1/+1 counters on it.

Vigilance

Embalm (, Exile this card from your graveyard: Create a token that's a copy of it, except it's a white Zombie Human Warrior with no mana cost. Embalm only as a sorcery.)

: Regenerate Unworthy Dead.

Flying

Sacrifice Unyaro Griffin: Counter target red instant or sorcery spell.

: Unyielding Krumar gains first strike until end of turn.

Upriser Renegade gets +2/+0 for each other modified creature you control. (Equipment, Auras you control, and counters are modifications.)

Creatures you control have haste.

Creatures your opponents control enter the battlefield tapped.

When Urabrask's Anointer enters the battlefield, it deals X damage to any target, where X is the number of permanents you control with oil counters on them.

When Urbis Protector enters the battlefield, create a 4/4 white Angel creature token with flying.

: Add , , or .

Kicker and/or (You may pay an additional and/or as you cast this spell.)

As Urborg Lhurgoyf enters the battlefield, mill three cards for each time it was kicked.

Urborg Lhurgoyf's power is equal to the number of creature cards in your graveyard and its toughness is equal to that number plus 1.

, Sacrifice Urborg Panther: Destroy target creature blocking Urborg Panther.

Sacrifice a creature named Feral Shadow, a creature named Breathstealer, and Urborg Panther: Search your library for a card named Spirit of the Night, put that card onto the battlefield, then shuffle.

Whenever Urborg Scavengers enters the battlefield or attacks, exile target card from a graveyard. Put a +1/+1 counter on Urborg Scavengers.

Urborg Scavengers has flying as long as a card exiled with it has flying. The same is true for first strike, double strike, deathtouch, haste, hexproof, indestructible, lifelink, menace, reach, trample, and vigilance.

Kicker <I>(You may pay an additional </I><I> as you cast this spell.)</I>

: Regenerate Urborg Skeleton.

If Urborg Skeleton was kicked, it enters the battlefield with a +1/+1 counter on it.

, , Discard a card: Each other player loses 2 life. You gain life equal to the life lost this way.

Flying

Whenever Urgoros, the Empty One deals combat damage to a player, that player discards a card at random. If the player can't, you draw a card.

When Uro enters the battlefield, sacrifice it unless it escaped.

Whenever Uro enters the battlefield or attacks, you gain 3 life and draw a card, then you may put a land card from your hand onto the battlefield.

Escape—, Exile five other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)

: Ursine Champion gets +3/+3 and becomes a Bear Berserker until end of turn. Activate only once each turn.

Whenever you cast a Myr spell, create a 1/1 colorless Myr artifact creature token.

At the beginning of combat on your turn, untap each Myr you control.

, : Put three +1/+1 counters on each Myr you control. Activate only during your turn.

Affinity for artifact creatures (This spell costs less to cast for each artifact creature you control.)

Artifact creatures you control have menace.

At the beginning of your end step, create a 0/0 colorless Construct artifact creature token with "This creature gets +1/+1 for each artifact you control."

Artifact, instant, and sorcery spells you cast cost less to cast.

: If you both own and control Urza, Lord Protector and an artifact named The Mightstone and Weakstone, exile them, then meld them into Urza, Planeswalker. Activate only as a sorcery.

Artifact creatures you control get +2/+2.

: Create a token that's a copy of target artifact you control, except it's a 1/1 Soldier creature in addition to its other types.

Trample

: Urza's Engine gains banding until end of turn. (Any creatures with banding, and up to one without, can attack in a band. Bands are blocked as a group. If any creatures with banding you control are blocking or being blocked by a creature, you divide that creature's combat damage, not its controller, among any of the creatures it's being blocked by or is blocking.)

: Attacking creatures banded with Urza's Engine gain trample until end of turn.

Return target permanent you control to its owner's hand. (Then exile this card. You may cast the creature later from exile.)

At the beginning of your upkeep, put a spore counter on Utopia Mycon.

Remove three spore counters from Utopia Mycon: Create a 1/1 green Saproling creature token.

Sacrifice a Saproling: Add one mana of any color.

Flying

Whenever a Dragon you control attacks, create a 6/6 red Dragon creature token with flying.

Uurg, Spawn of Turg's power is equal to the number of land cards in your graveyard.

At the beginning of your upkeep, surveil 1. (Look at the top card of your library. You may put that card into your graveyard.)

, Sacrifice a land: You gain 2 life.

Flying

, Return two lands you control to their owner's hand: Copy target instant or sorcery spell. You may choose new targets for the copy.

If it's neither day nor night, it becomes day as Vadrik, Astral Archmage enters the battlefield.

Instant and sorcery spells you cast cost less to cast, where X is Vadrik's power.

Whenever day becomes night or night becomes day, put a +1/+1 counter on Vadrik.

Flying

At the beginning of your upkeep, sacrifice Vaevictis Asmadi unless you pay .

: Vaevictis Asmadi gets +1/+0 until end of turn.

: Vaevictis Asmadi gets +1/+0 until end of turn.

: Vaevictis Asmadi gets +1/+0 until end of turn.

: Regenerate target creature with power 5 or greater.