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.'"

Mana Geyser

Add {R} for each tapped land your opponents control.

Harnfel, Horn of Bounty

Discard a card: Exile the top two cards of your library. You may play those cards this turn.

Birgi, God of Storytelling

Whenever you cast a spell, add {R}. Until end of turn, you don't lose this mana as steps and phases end.
Creatures you control can boast twice during each of your turns rather than once.

Birgi, God of Storytelling // Harnfel, Horn of Bounty

Hazoret's Monument

Red creature spells you cast cost {1} less to cast.
Whenever you cast a creature spell, you may discard a card. If you do, draw a card.

Pashalik Mons

Whenever Pashalik Mons or another Goblin you control dies, Pashalik Mons deals 1 damage to any target.
{3}{R}, Sacrifice a Goblin: Create two 1/1 red Goblin creature tokens.

Splinter Twin

Enchant creature
Enchanted creature has "{T}: Create a token that's a copy of this creature, except it has haste. Exile that token at the beginning of the next end step."

Squee, the Immortal

You may cast Squee, the Immortal from your graveyard or from exile.

Conspicuous Snoop

Play with the top card of your library revealed.
You may cast Goblin spells from the top of your library.
As long as the top card of your library is a Goblin card, Conspicuous Snoop has all activated abilities of that card.

Goldspan Dragon

Flying, haste
Whenever Goldspan Dragon attacks or becomes the target of a spell, create a Treasure token.
Treasures you control have "{T}, Sacrifice this artifact: Add two mana of any one color."

Goblin Sledder

Sacrifice a Goblin: Target creature gets +1/+1 until end of turn.

Valakut, the Molten Pinnacle

Valakut, the Molten Pinnacle enters tapped.
Whenever a Mountain you control enters, if you control at least five other Mountains, you may have Valakut, the Molten Pinnacle deal 3 damage to any target.
{T}: Add {R}.

Relentless Assault

Untap all creatures that attacked this turn. After this main phase, there is an additional combat phase followed by an additional main phase.

Goblin Recruiter

When Goblin Recruiter enters, search your library for any number of Goblin cards, reveal them, then shuffle and put those cards on top in any order.

Ruby Medallion

Red spells you cast cost {1} less to cast.

Faithless Looting

Draw two cards, then discard two cards.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Zealous Conscripts

Haste
When Zealous Conscripts enters, gain control of target permanent until end of turn. Untap that permanent. It gains haste until end of turn.

Magus of the Wheel

{1}{R}, {T}, Sacrifice Magus of the Wheel: Each player discards their hand, then draws seven cards.

Reiterate

Buyback {3} (You may pay an additional {3} as you cast this spell. If you do, put this card into your hand as it resolves.)
Copy target instant or sorcery spell. You may choose new targets for the copy.

Lightning Crafter

Champion a Goblin or Shaman (When this enters, sacrifice it unless you exile another Goblin or Shaman you control. When this leaves the battlefield, that card returns to the battlefield.)
{T}: Lightning Crafter deals 3 damage to any target.

Dualcaster Mage

Flash
When Dualcaster Mage enters, copy target instant or sorcery spell. You may choose new targets for the copy.

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}.

Kiki-Jiki, Mirror Breaker

Haste
{T}: Create a token that's a copy of target nonlegendary creature you control, except it has haste. Sacrifice it at the beginning of the next end step.

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control. It can attack and {T} no matter when it came under your control.)
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Jeska's Will

Choose one. If you control a commander as you cast this spell, you may choose both instead.
• Add {R} for each card in target opponent's hand.
• Exile the top three cards of your library. You may play them this turn.

Brash Taunter

Indestructible
Whenever Brash Taunter is dealt damage, it deals that much damage to target opponent.
{2}{R}, {T}: Brash Taunter fights another target creature.

Krenko, Mob Boss

{T}: Create X 1/1 red Goblin creature tokens, where X is the number of Goblins you control.

Ancient Tomb

{T}: Add {C}{C}. Ancient Tomb deals 2 damage to you.

Seething Song

Blood Moon

Twinflame

Strive — This spell costs {2}{R} more to cast for each target beyond the first.
Choose any number of target creatures you control. For each of them, create a token that's a copy of that creature, except it has haste. Exile those tokens at the beginning of the next end step.

Goblin Chieftain

Haste (This creature can attack and {T} as soon as it comes under your control.)
Other Goblin creatures you control get +1/+1 and have haste.

Idol of Oblivion

{T}: Draw a card. Activate only if you created a token this turn.
{8}, {T}, Sacrifice Idol of Oblivion: Create a 10/10 colorless Eldrazi creature token.

Thrill of Possibility

As an additional cost to cast this spell, discard a card.
Draw two cards.

Port Razer

Whenever Port Razer deals combat damage to a player, untap each creature you control. After this phase, there is an additional combat phase.
Port Razer can't attack a player it has already attacked this turn.

Throne of the God-Pharaoh

At the beginning of your end step, each opponent loses life equal to the number of tapped creatures you control.

Grinning Ignus

{R}, Return Grinning Ignus to its owner's hand: Add {C}{C}{R}. Activate only as a sorcery.

Skullclamp

Equipped creature gets +1/-1.
Whenever equipped creature dies, draw two cards.
Equip {1}

Combat Celebrant

If Combat Celebrant hasn't been exerted this turn, you may exert it as it attacks. When you do, untap all other creatures you control and after this phase, there is an additional combat phase. (An exerted creature won't untap during your next untap step.)

Goblin Warchief

Goblin spells you cast cost {1} less to cast.
Goblins you control have haste.

Skirk Prospector

Aggravated Assault

{3}{R}{R}: Untap all creatures you control. After this main phase, there is an additional combat phase followed by an additional main phase. Activate only as a sorcery.

Basilisk Collar

Equipped creature has deathtouch and lifelink. (Any amount of damage it deals to a creature is enough to destroy it. Damage dealt by this creature also causes you to gain that much life.)
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Mana Echoes

Whenever a creature enters, you may add an amount of {C} equal to the number of creatures you control that share a creature type with it.

Chaos Warp

The owner of target permanent shuffles it into their library, then reveals the top card of their library. If it's a permanent card, they put it onto the battlefield.

Krenko, Tin Street Kingpin

Whenever Krenko, Tin Street Kingpin attacks, put a +1/+1 counter on it, then create a number of 1/1 red Goblin creature tokens equal to Krenko's power.

Sol Ring

Snow-Covered Mountain

Goblin Sharpshooter

Goblin Sharpshooter doesn't untap during your untap step.
Whenever a creature dies, untap Goblin Sharpshooter.
{T}: Goblin Sharpshooter deals 1 damage to any target.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Nykthos, Shrine to Nyx

{T}: Add {C}.
{2}, {T}: Choose a color. Add an amount of mana of that color equal to your devotion to that color. (Your devotion to a color is the number of mana symbols of that color in the mana costs of permanents you control.)

Blazing Sunsteel

Equipped creature gets +1/+0 for each opponent you have.
Whenever equipped creature is dealt damage, it deals that much damage to any target.
Equip {4}

Brightstone Ritual

Add {R} for each Goblin on the battlefield.

Gamble

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

Dockside Extortionist

When Dockside Extortionist enters, 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.")

Goblin King

Other Goblins get +1/+1 and have mountainwalk.

Goblin Matron

When Goblin Matron enters, you may search your library for a Goblin card, reveal that card, put it into your hand, then shuffle.

Hammer of Purphoros

Creatures you control have haste.
{2}{R}, {T}, Sacrifice a land: Create a 3/3 colorless Golem enchantment artifact creature token.

Phyrexian Altar

Sacrifice a creature: Add one mana of any color.

Magus of the Moon

Dragon Mage

Flying
Whenever this creature deals combat damage to a player, each player discards their hand, then draws seven cards.

Legion Loyalist

Haste
Battalion — Whenever Legion Loyalist and at least two other creatures attack, creatures you control gain first strike and trample until end of turn and can't be blocked by creature tokens this turn.

Wheel of Fortune

Each player discards their hand, then draws seven cards.

Braid of Fire

Cumulative upkeep—Add {R}. (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.)

Purphoros, God of the Forge

Indestructible
As long as your devotion to red is less than five, Purphoros isn't a creature.
Whenever another creature you control enters, Purphoros deals 2 damage to each opponent.
{2}{R}: Creatures you control get +1/+0 until end of turn.