Box of Free-Range Goblins

Roll a six-sided die. Create a number of 1/1 red Goblin creature tokens equal to the result.

Shahrazad

Players play a Magic subgame, using their libraries as their decks. Each player who doesn't win the subgame loses half their life, rounded up.

The Deck of Many Things

{2}, {T}: Roll a d20 and subtract the number of cards in your hand. If the result is 0 or less, discard your hand.
1—9 | Return a card at random from your graveyard to your hand.
10—19 | Draw two cards.
20 | Put a creature card from any graveyard onto the battlefield under your control. When that creature dies, its owner loses the game.

Songs of the Damned

Add {B} for each creature card in your graveyard.

Enter the Dungeon

Players play a Magic subgame under the table, starting at 5 life and using their libraries as their decks. The winner searches their library for two cards, puts those cards into their hand, then shuffles.

Magus of the Coffers

{2}, {T}: Add {B} for each Swamp you control.

Demonic Tutor

Search your library for a card, put that card into your hand, then shuffle.

Some Disassembly Required

{B}, Sacrifice a creature: Distribute the sacrificed creature's keyword abilities among any number of other target creatures until end of turn. If it's December, you gain 1 life for each of those keywords.

Curse of the Fire Penguin Creature

Trample
When this creature dies, return Curse of the Fire Penguin to the battlefield.

Curse of the Fire Penguin

Enchant creature
Curse of the Fire Penguin consumes and confuses enchanted creature.

Curse of the Fire Penguin // Curse of the Fire Penguin Creature

Koth of the Hammer

+1: Untap target Mountain. It becomes a 4/4 red Elemental creature until end of turn. It's still a land.
−2: Add {R} for each Mountain you control.
−5: You get an emblem with "Mountains you control have '{T}: This land deals 1 damage to any target.'"

Bubbling Muck

Until end of turn, whenever a player taps a Swamp for mana, that player adds an additional {B}.

Cabal Ritual

Add {B}{B}{B}.
Threshold — Add {B}{B}{B}{B}{B} instead if seven or more cards are in your graveyard.

Orcish Librarian

{R}, {T}: Look at the top eight cards of your library. Exile four of them at random, then put the rest on top of your library in any order.

Arc-Slogger

{R}, Exile the top ten cards of your library: Arc-Slogger deals 2 damage to any target.

Rakdos Carnarium

Rakdos Carnarium enters the battlefield tapped.
When Rakdos Carnarium enters the battlefield, return a land you control to its owner's hand.
{T}: Add {B}{R}.

Culling the Weak

As an additional cost to cast this spell, sacrifice a creature.
Add {B}{B}{B}{B}.

Saw in Half

Destroy target creature. If that creature dies this way, its controller creates two tokens that are copies of that creature, except their base power is half that creature's power and their base toughness is half that creature's toughness. Round up each time.

Flamewave Invoker

{7}{R}: Flamewave Invoker deals 5 damage to target player or planeswalker.

Priest of Gix

When Priest of Gix enters the battlefield, add {B}{B}{B}.

Diabolical Salvation

Split second
Create four 4/4 red Devil creature tokens with haste and "When this creature dies, create a colorless Treasure artifact token with '{T}, Sacrifice this artifact: Add one mana of any color.'" Sacrifice the Devil tokens at the beginning of the next end step.

Cabal Coffers

Avatar of Fury

If an opponent controls seven or more lands, this spell costs {6} less to cast.
Flying
{R}: Avatar of Fury gets +1/+0 until end of turn.

Rocket-Powered Turbo Slug

Super haste (This may attack the turn before you cast it. (You may put this card from your hand onto the battlefield tapped and attacking during your declare attackers step. If you do, you lose the game at the beginning of your next turn's end step unless you pay this card's mana cost during that turn.))

Greater Gargadon

Suspend 10—{R}
Sacrifice an artifact, creature, or land: Remove a time counter from Greater Gargadon. Activate only if Greater Gargadon is suspended.

Rare-B-Gone

Each player sacrifices all permanents that are rare or mythic rare, then each player reveals their hand and discards all cards that are rare or mythic rare.

Cinder Marsh

{T}: Add {C}.
{T}: Add {B} or {R}. Cinder Marsh doesn't untap during your next untap step.

Summon the Pack

Open a sealed Magic booster pack, reveal the cards, and put all creature cards revealed this way onto the battlefield under your control. They're Zombies in addition to their other types. (Remove those cards from your deck before beginning a new game.)

Vessel of Volatility

{1}{R}, Sacrifice Vessel of Volatility: Add {R}{R}{R}{R}.

Swamp

The Countdown Is at One

Players play a Magic subgame, starting at 1 life and using their libraries as their decks. For the rest of the main game, if a source would deal damage to a player who didn't win the subgame, it deals double that damage to that player instead.

Mox Lotus

{T}: Add {∞}.
{100}: Add one mana of any color.

Doubling Cube

{3}, {T}: Double the amount of each type of unspent mana you have.

Cabal Stronghold

{T}: Add {C}.
{3}, {T}: Add {B} for each basic Swamp you control.

Auntie's Hovel

As Auntie's Hovel enters the battlefield, you may reveal a Goblin card from your hand. If you don't, Auntie's Hovel enters the battlefield tapped.
{T}: Add {B} or {R}.

Nirkana Revenant

Whenever you tap a Swamp for mana, add an additional {B}.
{B}: Nirkana Revenant gets +1/+1 until end of turn.

Destroy target creature with reminder text. (Reminder text is any italicized text in parentheses that explains rules you already know.)

Pygmy Giant

{R}, {T}, Sacrifice a creature: Pygmy Giant deals X damage to target creature, where X is a number in the sacrificed creature's text box.

Valakut Invoker

{8}: Valakut Invoker deals 3 damage to any target.

Gleemax

You choose all targets for all spells and abilities.

Goblin Artillery

{T}: Goblin Artillery deals 2 damage to any target and 3 damage to you.

Booster Tutor

Open a sealed Magic booster pack, reveal the cards, and put one of them into your hand. (Remove that card from your deck before beginning a new game.)

Spike, Tournament Grinder

({B/P} can be paid with either {B} or 2 life.)
{B/P}{B/P}{B/P}{B/P}: Reveal a card you own from outside the game that has been banned or restricted in a Constructed format and put it into your hand.

Seething Song

Bloodfell Caves

Bloodfell Caves enters the battlefield tapped.
When Bloodfell Caves enters the battlefield, you gain 1 life.
{T}: Add {B} or {R}.

Temple of Malice

Temple of Malice enters the battlefield tapped.
When Temple of Malice enters the battlefield, scry 1.
{T}: Add {B} or {R}.

Grusilda, Monster Masher

Combined, enchanted, and equipped creatures you control have menace.
{3}{B}{R}, {T}: Put two target creature cards from graveyards onto the battlefield combined into one creature under your control. (Its power is equal to their total power, its toughness is equal to their total toughness, and it has their names, mana costs, types, text boxes, etc.)

Dockside Extortionist

When Dockside Extortionist enters the battlefield, create X Treasure tokens, where X is the number of artifacts and enchantments your opponents control. (Treasure tokens are artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.")

Spoils of Evil

For each artifact or creature card in target opponent's graveyard, add {C} and you gain 1 life.

It That Gets Left Hanging

When It That Gets Left Hanging enters the battlefield, ask a person outside the game to high-five you. If they won't, It That Gets Left Hanging gains haste until end of turn.

Runaway Steam-Kin

Whenever you cast a red spell, if Runaway Steam-Kin has fewer than three +1/+1 counters on it, put a +1/+1 counter on Runaway Steam-Kin.
Remove three +1/+1 counters from Runaway Steam-Kin: Add {R}{R}{R}.

Dark Ritual

Garbage Elemental

Last strike (This creature deals combat damage after creatures without last strike.)
Battalion — Whenever Garbage Elemental and at least two other creatures attack, target creature can't block this turn.

Organ Harvest

Your team may sacrifice any number of creatures. For each creature sacrificed this way, you add {B}{B}.

Mountain

Cheatyface

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

Lake of the Dead

If Lake of the Dead would enter the battlefield, sacrifice a Swamp instead. If you do, put Lake of the Dead onto the battlefield. If you don't, put it into its owner's graveyard.
{T}: Add {B}.
{T}, Sacrifice a Swamp: Add {B}{B}{B}{B}.

Desperate Ritual

Add {R}{R}{R}.
Splice onto Arcane {1}{R} (As you cast an Arcane spell, you may reveal this card from your hand and pay its splice cost. If you do, add this card's effects to that spell.)

Infinity Elemental

Hammer Helper

Gain control of target creature until end of turn. Untap that creature and roll a six-sided die. Until end of turn, it gains haste and gets +X/+0, where X is the result.

The Big Idea

{2}{B/R}{B/R}, {T}: Roll a six-sided die. Create a number of 1/1 red Brainiac creature tokens equal to the result.
Tap three untapped Brainiacs you control: The next time you would roll a six-sided die, instead roll two six-sided dice and use the total of those results.