mtg.wtf

Whenever Xathrid Necromancer or another Human creature you control dies, create a tapped 2/2 black Zombie creature token.

{T}, Remove a counter from another permanent you control: Populate. Activate only as a sorcery.
{T}, Sacrifice another creature: Proliferate. Activate only as a sorcery.

Indestructible
As long as your devotion to red and green is less than seven, Xenagos isn't a creature.
At the beginning of combat on your turn, another target creature you control gains haste and gets +X/+X until end of turn, where X is that creature's power.

[+1]: Add X mana in any combination of {R} and/or {G}, where X is the number of creatures you control.
[0]: Create a 2/2 red and green Satyr creature token with haste.
[–6]: Exile the top seven cards of your library. You may put any number of creature and/or land cards from among them onto the battlefield.

Double strike
Auras you control have exalted.

Xenosquirrels enters with two +1/+1 counters on it.
After you roll a die, you may remove a +1/+1 counter from Xenosquirrels. If you do, increase or decrease the result by 1.

Whenever Xerex Squire attacks, calculate the hypotenuse of another creature you control. Xerex Squire's power and toughness become equal to that number, rounded up, until end of turn. (To calculate a hypotenuse, let A be that creature's power and B be that creature's toughness. Then C = ?(a² + b²). C is the hypotenuse. Or just look up a calculator online.)

Flying, vigilance
{T}: Create a 2/2 white and blue Knight creature token with vigilance. Activate only if you've cast two or more spells this turn.

Flying
{B}{R}{G}, {T}: Target player draws a card.

Flying, haste
Whenever Xira, the Golden Sting attacks, put an egg counter on another target creature without an egg counter on it. When that creature dies, if it has an egg counter on it, draw a card and create a 1/1 black Insect creature token with flying.

Whenever Xolatoyac, the Smiling Flood enters or attacks, put a flood counter on target land. That land is an Island in addition to its other types for as long as it has a flood counter on it.
At the beginning of your end step, untap each permanent you control with a counter on it.

If you would create one or more Treasure tokens, instead create those tokens plus an additional Treasure token.

{T}: Target creature you control gets +2/+0 until end of turn. Activate only during your turn, before attackers are declared.

Flying
Whenever an opponent draws a card except the first one they draw in each of their draw steps, create a 1/1 green Snake creature token.
Whenever Xyris, the Writhing Storm deals combat damage to a player, you and that player each draw that many cards.

Flying
Whenever Xyru Specter deals damage to an opponent, that player discards a card unless they challenge you. If challenged, and you show them two black cards in your hand, they must discard two cards.

All creatures get -3/-3 until end of turn.
You may cast a spell with mana value 3 or less from your hand without paying its mana cost.

Haste
Whenever a creature an opponent controls dies, put a +1/+1 counter on Yahenni, Undying Partisan.
Sacrifice another creature: Yahenni gains indestructible until end of turn.

Flying
When Yanling's Harbinger enters, you may search your library and/or graveyard for a card named Mu Yanling, Celestial Wind, reveal it, and put it into your hand. If you search your library this way, shuffle.

Partner with Nikara, Lair Scavenger
Vigilance
When Yannik, Scavenging Sentinel enters, exile another creature you control until Yannik leaves the battlefield. When you do, distribute X +1/+1 counters among any number of target creatures, where X is the exiled creature's power.

When Yarok's Fenlurker enters, each opponent exiles a card from their hand.
{2}{B}: Yarok's Fenlurker gets +1/+1 until end of turn.

When Yarok's Wavecrasher enters, return another creature you control to its owner's hand.

Deathtouch, lifelink
If a permanent entering causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Other creatures you control have haste.
Whenever one or more face-down creatures you control deal combat damage to a player, draw a card.
Whenever a face-down creature you control dies, return it to the battlefield face down under its owner's control if it's a permanent card, then turn it face up.