Exile target attacking creature. Then remove it from the game. Then put it into the absolutely-removed-from-the-freaking-game-forever zone.
{2}{G}{W}
Applejack
Legendary Creature - Pony
Family Gathering -- At the beginning of your end step, put a toy you own onto the battlefield as a 2/2 creature token with that toy's name, colors, and creature types. If the toy has wings, the token has flying. If the toy has a horn, scry 2. If it has neither, create a Food token.
4 /
4
{2}{U}
Artful Looter
Creature - Human Wizard
{T}: Draw a card, then discard a card.
Whenever a permanent that shares an artist with another permanent you control enters the battlefield, untap Artful Looter.
1 /
2
{1}{W}{B}
Ass Whuppin'
Sorcery
Destroy target silver-bordered or acorn permanent in any game you can see from your seat.
{3}{W}
Bill the Pony
Legendary Creature - Horse
When Bill the Pony enters the battlefield, create two Food tokens. (They're artifacts with "{2}, {T}, Sacrifice this artifact: You gain 3 life.")
Sacrifice a Food: Until end of turn, target creature you control assigns combat damage equal to its toughness rather than its power.
1 /
4
{4}
Border Guardian
Artifact Creature - Knight
Whenever you cast a silver-bordered spell, put a +1/+1 counter on Border Guardian.
Whenever you cast a black-bordered spell, Border Guardian can't be blocked this turn.
Whenever you cast a white-bordered spell, Border Guardian gains double strike until end of turn.
1 /
1
{4}
Buzzing Whack-a-Doodle
Artifact
As Buzzing Whack-a-Doodle enters the battlefield, you and an opponent each secretly choose Whack or Doodle. Then those choices are revealed. If the choices match, Buzzing Whack-a-Doodle has that ability. Otherwise, it has Buzz.
• Whack -- {T}: Target player loses 2 life.
• Doodle -- {T}: You gain 3 life.
• Buzz -- {2}, {T}: Draw a card.
{U}{U}{U}
Cheatyface
Creature - Efreet
If Cheatyface is in your hand, you may sneak Cheatyface onto the battlefield. If an opponent catches you right away, that player may exile Cheatyface.
Flying
2 /
2
--
City of Ass
Land
City of Ass enters the battlefield tapped.
{T}: Add one and one-half mana of any one color.
{3}
Clay Pigeon
Artifact Creature - Bird
Flying
{1}, Throw Clay Pigeon into the air at least two feet above your head while seated: If you catch Clay Pigeon with one hand, prevent all damage a source of your choice would deal to you this turn and tap Clay Pigeon. Otherwise, sacrifice it.
1 /
1
{3}{U}{U}
Clocknapper
Creature - Human Spy
When Clocknapper enters the battlefield, choose beginning phase, precombat main phase, combat phase, postcombat main phase, or ending phase. Steal that phase from target player during their next turn. (That phase occurs as though it's your turn instead.)
2 /
2
{2}{U}{U}
Common Courtesy
Enchantment
Whenever a player casts a spell without asking your permission while casting it, counter that spell.
When a player asks you permission to cast a spell and you refuse, counter that spell and sacrifice Common Courtesy.
{R}
Crash Through
Sorcery
Creatures you control gain trample until end of turn. (A creature with trample can deal excess combat damage to the player or planeswalker it's attacking.)
Draw a card.
{3}{W}{W}
Crested Sunmare
Creature - Horse
Other Horses you control have indestructible.
At the beginning of each end step, if you gained life this turn, create a 5/5 white Horse creature token.
5 /
5
{3}{U}{ // }{2}{U}
Decorated Knight // Present Arms
Creature - Human Knight // Sorcery - Adventure
Whenever Decorated Knight attacks, draw a card from your original deck if it's outside the game.
Exchange your library with another deck you own from outside the game. Shuffle your library.
3 /
3
{3}{U}{U}
Double Header
Creature - Drake
Flying
When Double Header enters the battlefield, you may return target permanent with a two-word name to its owner's hand.
2 /
3
{1}{G}{W}
Fluttershy
Legendary Creature - Pegasus
Defender, flying
{1}, {T}: Put a +1/+1 counter on each creature with a tail target player controls. Stare down up to one target creature until end of turn. (It can't attack or block as long as you're looking directly at it.)
0 /
4
{2}{U}
Fowl Play
Enchantment - Aura
Enchant creature
Enchanted creature loses all abilities and is a Bird creature with base power and toughness 1/1.
{3}{U}
Gifts Given
Instant
Search target opponent's library for four cards with different names and reveal them. That player chooses two of those cards. Put the chosen cards into the player's graveyard and the rest into your hand. Then that player shuffles their library.
{X}{X}{G}{G}
Hydradoodle
Creature - Hydra Dog
As Hydradoodle enters the battlefield, roll X six-sided dice. Hydradoodle enters the battlefield with a number of +1/+1 counters on it equal to the total of those results.
Reach, trample
0 /
0
{W}{W}
Knight of the Hokey Pokey
Creature - Knight
First strike
{1}{W}, Do the Hokey Pokey: Prevent all damage a source of your choice would deal to Knight of the Hokey Pokey this turn. (To do the Hokey Pokey, choose an arm, a leg, or your whole self and put it in. Put it out. Put it in. Shake it all about. You do the Hokey Pokey! Turn yourself around.)
2 /
2
{W}{W}
Knight of the Kitchen Sink
Artifact Creature - Cyborg Knight
First strike, protection from black borders (Nothing with a black border can block, target, deal damage to, or attach to this creature.)
2 /
2
{1}{W}{W}
Man of Measure
Creature - Human Knight
As long as you're shorter than an opponent, Man of Measure gets +0/+1 and has first strike.
As long as you're taller than an opponent, Man of Measure gets +1/+0.
2 /
2
--
Mishra's Toy Workshop
Land
{T}: Add {C}{C}{C}. Spend this mana only on spells and abilities that put tokens onto the battlefield. Use toys to represent the tokens.
{3}{G}
Monkey Monkey Monkey
Creature - Monkey
As Monkey Monkey Monkey enters the battlefield, choose a letter.
Monkey Monkey Monkey gets +1/+1 for each nonland permanent whose name begins with the chosen letter.
1 /
1
{4}{B}{B}
Nightmare Moon
Legendary Creature - Alicorn
Flying
As long as it's nighttime, Nightmare Moon gets +2/+2 and has menace.
{6}: Transform Nightmare Moon. Anypony may activate this ability or help pay the cost. When they do, they become your friend.
6 /
6
--
Princess Luna
Legendary Creature - Alicorn
Flying
When this creature transforms into Princess Luna, choose up to six cards you own from outside the game with a moon in their art, then exile those cards. As long as those cards remain exiled, you may cast them, and your friends may cast them with your permission. (Gifts are appreciated.)
6 /
6
{G}{G}
Old Fogey
Summon - Dinosaur
Phasing, cumulative upkeep {1}, echo {G}{G}, fading 3, bands with other Dinosaurs, protection from Homarids, snow-covered plainswalk, flanking, rampage 2
7 /
7
{3}
Opaline Unicorn
Artifact Creature - Unicorn
{T}: Add one mana of any color.
1 /
2
{R}{W}
Pinkie Pie
Legendary Creature - Pony
Whenever you cast a spell with a smile in its art, create a tapped Treasure token.
Everypony's Invited -- Your party consists of each creature you control, and your party is always full.
2 /
2
{W}{U}
Princess Twilight Sparkle
Legendary Creature - Alicorn
Flying
Other Alicorns, Horses, Pegasi, Ponies, and Unicorns you control get +1/+1.
{W}{U}{B}{R}{G}: If you control Applejack, Fluttershy, Pinkie Pie, Rainbow Dash, and Rarity, everypony wins the game.
2 /
2
{1}{R}{W}
Rainbow Dash
Legendary Creature - Pegasus
Flying, haste
Whenever a creature you control with flying and/or haste attacks, you get 20% cooler. (You start at 0% coolness.)
Sonic Rainboom -- {T}: If you're at least 100% cool, add {W}{U}{B}{R}{G}, draw a card, and reset your coolness.
2 /
2
{1}{W}{U}
Rarity
Legendary Creature - Unicorn
Rare and mythic rare spells you cast cost {1} less to cast.
{1}, {T}, Reveal a My Little Pony® toy you own: Until end of turn, another target creature gains protection from each color in that toy's coat, mane, and outfit.
2 /
2
{1}{G}{G}
Shellephant
Creature - Turtle and/or Elephant
{0}: Choose one. You may activate this ability while Shellephant is in any zone.
• Shellephant has base power and toughness 1/4.
• Shellephant has base power and toughness 3/3.
? /
?
{4}{U}{U}
Sun Quan, Lord of Wu
Legendary Creature - Human Soldier
Creatures you control have horsemanship. (They can't be blocked except by creatures with horsemanship.)
4 /
4
{3}{G}
Surgeon General Commander
Legendary Creature - Wombat Bat Chameleon
Whenever you augment, enchant, or mutate a creature you control, draw a card.
{T}: Add {W}, {U}, {B}, {R}, or {G}.
3 /
3
{2}{G}{G}
Timmy, Power Gamer
Legendary Creature - Human Gamer
{4}: You may put a creature card from your hand onto the battlefield.
1 /
1
--
Underdome
Land
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to pay Un-costs.
--
Watermarket
Land
{T}: Add {C}{C}. Spend this mana only to cast spells with watermarks.
{1}{G}
Wild Crocodile
Host Creature - Crocodile
When this creature enters the battlefield, search your library for a basic land card, reveal it, put it into your hand, then shuffle.
1 /
1
{2}{G}{W}
Zebra Unicorn
Creature - Unicorn
Whenever Zebra Unicorn deals damage, you gain that much life.
2 /
2
{3}{G}
Zodiac Horse
Creature - Horse
Islandwalk (This creature can't be blocked as long as defending player controls an Island.)
3 /
3
{2}{B}{B}
capital offense
instant
target creature gets -x/-x until end of turn, where x is the number of times a capital letter appears in its rules text. (ignore reminder text and flavor text.)