Antagonize

Target creature gets +4/+3 until end of turn.

Bloodmark Mentor

Red creatures you control have first strike.

Mogg Infestation

Destroy all creatures target player controls. For each creature that died this way, that player creates two 1/1 red Goblin creature tokens.

Price of Glory

Whenever a player taps a land for mana, if it's not that player's turn, destroy that land.

Battle Cry Goblin

{1}{R}: Goblins you control get +1/+0 and gain haste until end of turn.
Whenever Battle Cry Goblin attacks, if you attacked with creatures with total power 6 or greater this combat, create a 1/1 red Goblin creature token that's tapped and attacking.

Mountain

Etali, Primal Storm

Whenever Etali attacks, exile the top card of each player's library, then you may cast any number of spells from among those cards without paying their mana costs.

Krenko, Mob Boss

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

Den of the Bugbear

If you control two or more other lands, Den of the Bugbear enters tapped.
{T}: Add {R}.
{3}{R}: Until end of turn, Den of the Bugbear becomes a 3/2 red Goblin creature with "Whenever this creature attacks, create a 1/1 red Goblin creature token that's tapped and attacking." It's still a land.

Door of Destinies

As Door of Destinies enters, choose a creature type.
Whenever you cast a spell of the chosen type, put a charge counter on Door of Destinies.
Creatures you control of the chosen type get +1/+1 for each charge counter on Door of Destinies.

Vexing Devil

When Vexing Devil enters, any opponent may have it deal 4 damage to them. If a player does, sacrifice Vexing Devil.

Shared Animosity

Whenever a creature you control attacks, it gets +1/+0 until end of turn for each other attacking creature that shares a creature type with it.

Ben-Ben, Akki Hermit

{T}: Ben-Ben, Akki Hermit deals damage to target attacking creature equal to the number of untapped Mountains you control.

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.

Mox Ruby

Caterwauling Boggart

Goblins you control and Elementals you control have menace. (They can't be blocked except by two or more creatures.)

Boggart Shenanigans

Whenever another Goblin you control is put into a graveyard from the battlefield, you may have Boggart Shenanigans deal 1 damage to target player or planeswalker.

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}.

Coat of Arms

Each creature gets +1/+1 for each other creature on the battlefield that shares at least one creature type with it. (For example, if two Goblin Warriors and a Goblin Shaman are on the battlefield, each gets +2/+2.)

Zo-Zu the Punisher

Whenever a land enters, Zo-Zu the Punisher deals 2 damage to that land's controller.

Goblin Grenade

As an additional cost to cast this spell, sacrifice a Goblin.
Goblin Grenade deals 5 damage to any target.

Goblin Caves

Enchant land
As long as enchanted land is a basic Mountain, Goblin creatures get +0/+2.

Goblin Gardener

When Goblin Gardener dies, destroy target land.

Molten Rain

Destroy target land. If that land was nonbasic, Molten Rain deals 2 damage to the land's controller.

Quest for the Goblin Lord

Whenever a Goblin you control enters, you may put a quest counter on Quest for the Goblin Lord.
As long as Quest for the Goblin Lord has five or more quest counters on it, creatures you control get +2/+0.

Muxus, Goblin Grandee

When Muxus, Goblin Grandee enters, reveal the top six cards of your library. Put all Goblin creature cards with mana value 5 or less from among them onto the battlefield and the rest on the bottom of your library in a random order.
Whenever Muxus attacks, it gets +1/+1 until end of turn for each other Goblin you control.

Chimney Rabble

Haste
When Chimney Rabble enters, create a 1/1 red Phyrexian Goblin creature token.

Boggart Ram-Gang

Haste
Wither (This deals damage to creatures in the form of -1/-1 counters.)

Anger

Haste
As long as Anger is in your graveyard and you control a Mountain, creatures you control have haste.

Hulking Bugbear

Dormant Volcano

Dormant Volcano enters tapped.
When Dormant Volcano enters, sacrifice it unless you return an untapped Mountain you control to its owner's hand.
{T}: Add {C}{R}.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Goblin Dark-Dwellers

Menace (This creature can't be blocked except by two or more creatures.)
When Goblin Dark-Dwellers enters, you may cast target instant or sorcery card with mana value 3 or less from your graveyard without paying its mana cost. If that spell would be put into your graveyard, exile it instead.

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.

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.

Hammer of Purphoros

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

Horde of Boggarts

Menace (This creature can't be blocked except by two or more creatures.)
Horde of Boggarts's power and toughness are each equal to the number of red permanents you control.

Ignition Team

Ignition Team enters with X +1/+1 counters on it, where X is the number of tapped lands on the battlefield.
{2}{R}, Remove a +1/+1 counter from Ignition Team: Target land becomes a 4/4 red Elemental creature until end of turn. It's still a land.

Obelisk of Urd

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
As Obelisk of Urd enters, choose a creature type.
Creatures you control of the chosen type get +2/+2.

Smash to Smithereens

Destroy target artifact. Smash to Smithereens deals 3 damage to that artifact's controller.

Emberwilde Augur

Sacrifice Emberwilde Augur: It deals 3 damage to target player or planeswalker. Activate only during your upkeep.

Cacophony Scamp

Whenever Cacophony Scamp deals combat damage to a player, you may sacrifice it. If you do, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)
When Cacophony Scamp dies, it deals damage equal to its power to any target.