Squee's Revenge

Choose a number. Flip a coin that many times or until you lose a flip, whichever comes first. If you win all the flips, draw two cards for each flip.

Creepy Doll

Indestructible
Whenever Creepy Doll deals combat damage to a creature, flip a coin. If you win the flip, destroy that creature.

Game of Chaos

Flip a coin. If you win the flip, you gain 1 life and target opponent loses 1 life, and you decide whether to flip again. If you lose the flip, you lose 1 life and that opponent gains 1 life, and that player decides whether to flip again. Double the life stakes with each flip.

Karplusan Minotaur

Cumulative upkeep—Flip a coin. (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
Whenever you win a coin flip, Karplusan Minotaur deals 1 damage to any target.
Whenever you lose a coin flip, Karplusan Minotaur deals 1 damage to any target of an opponent's choice.

Goblin Archaeologist

{R}, {T}: Flip a coin. If you win the flip, destroy target artifact and untap Goblin Archaeologist. If you lose the flip, sacrifice Goblin Archaeologist.

Okaun, Eye of Chaos

Partner with Zndrsplt, Eye of Wisdom (When this creature enters, target player may put Zndrsplt into their hand from their library, then shuffle.)
At the beginning of combat on your turn, flip a coin until you lose a flip.
Whenever a player wins a coin flip, double Okaun's power and toughness until end of turn.

Goblin Festival

{2}: Goblin Festival deals 1 damage to any target. Flip a coin. If you lose the flip, choose one of your opponents. That player gains control of Goblin Festival.

Scoria Wurm

At the beginning of your upkeep, flip a coin. If you lose the flip, return Scoria Wurm to its owner's hand.

Molten Sentry

As Molten Sentry enters, flip a coin. If the coin comes up heads, Molten Sentry enters as a 5/2 creature with haste. If it comes up tails, Molten Sentry enters as a 2/5 creature with defender.

Goblin Kaboomist

At the beginning of your upkeep, create a colorless artifact token named Land Mine with "{R}, Sacrifice this artifact: This artifact deals 2 damage to target attacking creature without flying." Then flip a coin. If you lose the flip, Goblin Kaboomist deals 2 damage to itself.

Tide of War

Whenever one or more creatures block, flip a coin. If you win the flip, each blocking creature is sacrificed by its controller. If you lose the flip, each blocked creature is sacrificed by its controller.

Two-Headed Giant

Whenever Two-Headed Giant attacks, flip two coins. If both coins come up heads, Two-Headed Giant gains double strike until end of turn. If both coins come up tails, Two-Headed Giant gains menace until end of turn.

Goblin Psychopath

Whenever Goblin Psychopath attacks or blocks, flip a coin. If you lose the flip, the next time it would deal combat damage this turn, it deals that damage to you instead.

Goblin Bangchuckers

{T}: Flip a coin. If you win the flip, Goblin Bangchuckers deals 2 damage to any target. If you lose the flip, Goblin Bangchuckers deals 2 damage to itself.

Goblin Assassin

Whenever Goblin Assassin or another Goblin enters, each player flips a coin. Each player whose coin comes up tails sacrifices a creature.

Wirefly Hive

{3}, {T}: Flip a coin. If you win the flip, create a 2/2 colorless Insect artifact creature token with flying named Wirefly. If you lose the flip, destroy all permanents named Wirefly.

Zndrsplt, Eye of Wisdom

Partner with Okaun, Eye of Chaos (When this creature enters, target player may put Okaun into their hand from their library, then shuffle.)
At the beginning of combat on your turn, flip a coin until you lose a flip.
Whenever a player wins a coin flip, draw a card.

Ydwen Efreet

Whenever Ydwen Efreet blocks, flip a coin. If you lose the flip, remove Ydwen Efreet from combat and it can't block this turn. Creatures it was blocking that had become blocked by only Ydwen Efreet this combat become unblocked.

Crooked Scales

{4}, {T}: Flip a coin. If you win the flip, destroy target creature an opponent controls. If you lose the flip, destroy target creature you control unless you pay {3} and repeat this process.

Risky Move

At the beginning of each player's upkeep, that player gains control of Risky Move.
When you gain control of Risky Move from another player, choose a creature you control and an opponent. Flip a coin. If you lose the flip, that opponent gains control of that creature.

Mana Crypt

At the beginning of your upkeep, flip a coin. If you lose the flip, Mana Crypt deals 3 damage to you.
{T}: Add {C}{C}.

Mirror March

Whenever a nontoken creature you control enters, flip a coin until you lose a flip. For each flip you won, create a token that's a copy of that creature. Those tokens gain haste. Exile them at the beginning of the next end step.

Chaotic Goo

Chaotic Goo enters with three +1/+1 counters on it.
At the beginning of your upkeep, you may flip a coin. If you win the flip, put a +1/+1 counter on Chaotic Goo. If you lose the flip, remove a +1/+1 counter from Chaotic Goo.

Orcish Captain

{1}: Flip a coin. If you win the flip, target Orc creature gets +2/+0 until end of turn. If you lose the flip, it gets -0/-2 until end of turn.

Krark's Thumb

If you would flip a coin, instead flip two coins and ignore one.

Volatile Rig

Trample
Volatile Rig attacks each combat if able.
Whenever Volatile Rig is dealt damage, flip a coin. If you lose the flip, sacrifice Volatile Rig.
When Volatile Rig dies, flip a coin. If you lose the flip, it deals 4 damage to each creature and each player.

Skittish Valesk

At the beginning of your upkeep, flip a coin. If you lose the flip, turn Skittish Valesk face down.
Morph {5}{R} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Fiery Gambit

Flip a coin until you lose a flip or choose to stop flipping. If you lose a flip, Fiery Gambit has no effect. If you win one or more flips, Fiery Gambit deals 3 damage to target creature. If you win two or more flips, Fiery Gambit deals 6 damage to each opponent. If you win three or more flips, draw nine cards and untap all lands you control.

Goblin Bookie

{R}, {T}: Reflip any coin or reroll any die. (Activate only any time it makes sense.)

Ral Zarek

+1: Tap target permanent, then untap another target permanent.
−2: Ral Zarek deals 3 damage to any target.
−7: Flip five coins. Take an extra turn after this one for each coin that comes up heads.

Goblin Bomb

At the beginning of your upkeep, you may flip a coin. If you win the flip, put a fuse counter on Goblin Bomb. If you lose the flip, remove a fuse counter from Goblin Bomb.
Remove five fuse counters from Goblin Bomb and sacrifice it: It deals 20 damage to target player or planeswalker.

Impulsive Maneuvers

Whenever a creature attacks, flip a coin. If you win the flip, the next time that creature would deal combat damage this turn, it deals double that damage instead. If you lose the flip, the next time that creature would deal combat damage this turn, prevent that damage.

Mana Screw

{1}: Flip a coin. If you win the flip, add {C}{C}. Activate only as an instant.

Stitch in Time

Flip a coin. If you win the flip, take an extra turn after this one.

Planar Chaos

At the beginning of your upkeep, flip a coin. If you lose the flip, sacrifice Planar Chaos.
Whenever a player casts a spell, that player flips a coin. If they lose the flip, counter that spell.

Mogg Assassin

{T}: You choose target creature an opponent controls, and that opponent chooses target creature. Flip a coin. If you win the flip, destroy the creature you chose. If you lose the flip, destroy the creature your opponent chose.

Molten Birth

Create two 1/1 red Elemental creature tokens, then flip a coin. If you win the flip, return Molten Birth to its owner's hand.

Chance Encounter

Whenever you win a coin flip, put a luck counter on Chance Encounter.
At the beginning of your upkeep, if Chance Encounter has ten or more luck counters on it, you win the game.