Staff of the Flame Magus

Whenever you cast a red spell or a Mountain you control enters, you gain 1 life.

Mogg Flunkies

Mogg Flunkies can't attack or block alone.

Goblin Rabblemaster

Other Goblin creatures you control attack each combat if able.
At the beginning of combat on your turn, create a 1/1 red Goblin creature token with haste.
Whenever Goblin Rabblemaster attacks, it gets +1/+0 until end of turn for each other attacking Goblin.

Lavastep Raider

{2}{R}: Lavastep Raider gets +2/+0 until end of turn.

Goblin Roughrider

Outnumber

Outnumber deals damage to target creature equal to the number of creatures you control.

Magmatic Chasm

Creatures without flying can't block this turn.

Kyren Glider

Vial of Dragonfire

{2}, {T}, Sacrifice Vial of Dragonfire: It deals 2 damage to target creature.

Krenko, Mob Boss

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

Koth, Fire of Resistance

+2: Search your library for a basic Mountain card, reveal it, put it into your hand, then shuffle.
−3: Koth, Fire of Resistance deals damage to target creature equal to the number of Mountains you control.
−7: You get an emblem with "Whenever a Mountain you control enters, this emblem deals 4 damage to any target."

Skeleton Key

Equipped creature has skulk. (It can't be blocked by creatures with greater power.)
Whenever equipped creature deals combat damage to a player, you may draw a card. If you do, discard a card.
Equip {2}

Senseless Rage

Enchant creature
Enchanted creature gets +2/+2.
Madness {1}{R} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Rush of Adrenaline

Target creature gets +2/+1 and gains trample until end of turn.

Goblin Swine-Rider

Whenever Goblin Swine-Rider becomes blocked, it deals 2 damage to each attacking creature and each blocking creature.

Survey the Wreckage

Destroy target land. Create a 1/1 red Goblin creature token.

Brain in a Jar

{1}, {T}: Put a charge counter on Brain in a Jar, then you may cast an instant or sorcery spell with mana value equal to the number of charge counters on Brain in a Jar from your hand without paying its mana cost.
{3}, {T}, Remove X charge counters from Brain in a Jar: Scry X.

Sure Strike

Target creature gets +3/+0 and gains first strike until end of turn.

Press into Service

Support 2. (Put a +1/+1 counter on each of up to two target creatures.)
Gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn.

Impact Tremors

Whenever a creature you control enters, Impact Tremors deals 1 damage to each opponent.

Frenzied Goblin

Whenever Frenzied Goblin attacks, you may pay {R}. If you do, target creature can't block this turn.

Call of the Full Moon

Enchant creature
Enchanted creature gets +3/+2 and has trample. (It can deal excess combat damage to the player or planeswalker it's attacking.)
At the beginning of each upkeep, if a player cast two or more spells last turn, sacrifice Call of the Full Moon.

Evolving Wilds

{T}, Sacrifice Evolving Wilds: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Hobgoblin Bandit Lord

Other Goblins you control get +1/+1.
{R}, {T}: Hobgoblin Bandit Lord deals damage equal to the number of Goblins that entered the battlefield under your control this turn to any target.

Kyren Sniper

At the beginning of your upkeep, you may have Kyren Sniper deal 1 damage to target player or planeswalker.

Goblinslide

Whenever you cast a noncreature spell, you may pay {1}. If you do, create a 1/1 red Goblin creature token with haste.

Goblin Warchief

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

Deathrender

Equipped creature gets +2/+2.
Whenever equipped creature dies, you may put a creature card from your hand onto the battlefield and attach Deathrender to it.
Equip {2}

Magnifying Glass

{T}: Add {C}.
{4}, {T}: Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Goblin Elite Infantry

Whenever Goblin Elite Infantry blocks or becomes blocked, it gets -1/-1 until end of turn.

Goblin Freerunner

Surge {1}{R} (You may cast this spell for its surge cost if you or a teammate has cast another spell this turn.)
Menace (This creature can't be blocked except by two or more creatures.)

Goblin Spelunkers

Mountainwalk (This creature can't be blocked as long as defending player controls a Mountain.)

Grenzo's Cutthroat

First strike
Dethrone (Whenever this creature attacks the player with the most life or tied for most life, put a +1/+1 counter on it.)

Looming Spires

Looming Spires enters tapped.
When Looming Spires enters, target creature gets +1/+1 and gains first strike until end of turn.
{T}: Add {R}.

Foundry Street Denizen

Whenever another red creature you control enters, Foundry Street Denizen gets +1/+0 until end of turn.

Warstorm Surge

Whenever a creature you control enters, it deals damage equal to its power to any target.

Coordinated Assault

Up to two target creatures each get +1/+0 and gain first strike until end of turn.

Keeper of Kookus

{R}: Keeper of Kookus gains protection from red until end of turn.

Goblin War Paint

Enchant creature
Enchanted creature gets +2/+2 and has haste.

Siege-Gang Commander

When Siege-Gang Commander enters, create three 1/1 red Goblin creature tokens.
{1}{R}, Sacrifice a Goblin: Siege-Gang Commander deals 2 damage to any target.

Subterranean Scout

When Subterranean Scout enters, target creature with power 2 or less can't be blocked this turn.

Goblin Furrier

Prevent all damage that Goblin Furrier would deal to snow creatures.

Retreat to Valakut

Landfall — Whenever a land you control enters, choose one —
• Target creature gets +2/+0 until end of turn.
• Target creature can't block this turn.

Goro-Goro, Disciple of Ryusei

{R}: Creatures you control gain haste until end of turn.
{3}{R}{R}: Create a 5/5 red Dragon Spirit creature token with flying. Activate only if you control an attacking modified creature. (Equipment, Auras you control, and counters are modifications.)

Mountain

Quicksand

{T}: Add {C}.
{T}, Sacrifice Quicksand: Target attacking creature without flying gets -1/-2 until end of turn.

Skinwing

Living weapon (When this Equipment enters, create a 0/0 black Phyrexian Germ creature token, then attach this to it.)
Equipped creature gets +2/+2 and has flying.
Equip {6}

True-Faith Censer

Equipped creature gets +1/+1 and has vigilance.
As long as equipped creature is a Human, it gets an additional +1/+0.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Zada, Hedron Grinder

Whenever you cast an instant or sorcery spell that targets only Zada, Hedron Grinder, copy that spell for each other creature you control that the spell could target. Each copy targets a different one of those creatures.

Spitting Earth

Spitting Earth deals damage to target creature equal to the number of Mountains you control.

Cursed Mirror

{T}: Add {R}.
As Cursed Mirror enters, you may have it become a copy of any creature on the battlefield until end of turn, except it has haste.

Spiteful Motives

Flash (You may cast this spell any time you could cast an instant.)
Enchant creature
Enchanted creature gets +3/+0 and has first strike.

Goblin Raider

Goblin Vandal

Whenever Goblin Vandal attacks and isn't blocked, you may pay {R}. If you do, destroy target artifact defending player controls and Goblin Vandal assigns no combat damage this turn.

Goblin Heelcutter

Whenever Goblin Heelcutter attacks, target creature can't block this turn.
Dash {2}{R} (You may cast this spell for its dash cost. If you do, it gains haste, and it's returned from the battlefield to its owner's hand at the beginning of the next end step.)

Enslaved Scout

{2}: Enslaved Scout gains mountainwalk until end of turn. (It can't be blocked as long as defending player controls a Mountain.)

Boggart Brute

Menace (This creature can't be blocked except by two or more creatures.)

Kyren Legate

If an opponent controls a Plains and you control a Mountain, you may cast this spell without paying its mana cost.
Haste

Uncaged Fury

Target creature gets +1/+1 and gains double strike until end of turn. (It deals both first-strike and regular combat damage.)

Guttersnipe

Whenever you cast an instant or sorcery spell, Guttersnipe deals 2 damage to each opponent.

Goblin Caves

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

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}.

Goblin Cadets

Whenever Goblin Cadets blocks or becomes blocked, target opponent gains control of it. (This removes Goblin Cadets from combat.)

Dragon Fodder

Create two 1/1 red Goblin creature tokens.

Ulamog's Crusher

Annihilator 2 (Whenever this creature attacks, defending player sacrifices two permanents.)
Ulamog's Crusher attacks each combat if able.

Goblin Piledriver

Protection from blue (This creature can't be blocked, targeted, dealt damage, or enchanted by anything blue.)
Whenever Goblin Piledriver attacks, it gets +2/+0 until end of turn for each other attacking Goblin.