Have

Mana Geyser

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

Mountain

Siege-Gang Commander

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

Mogg War Marshal

Echo {1}{R} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)
When this creature enters or dies, create a 1/1 red Goblin creature token.

Runaway Steam-Kin

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

Hedron Crawler

{T}: Add {C}. ({C} represents colorless mana.)

Spark of Creativity

Choose target creature. Exile the top card of your library. You may have Spark of Creativity deal damage to that creature equal to the exiled card's mana value. If you don't, you may play that card until end of turn.

Bolt Bend

This spell costs {3} less to cast if you control a creature with power 4 or greater.
Change the target of target spell or ability with a single target.

Zada, Hedron Grinder

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

Beetleback Chief

When this creature enters, create two 1/1 red Goblin creature tokens.

Inner Fire

Chain Reaction

Chain Reaction deals X damage to each creature, where X is the number of creatures on the battlefield.

Titan's Strength

Target creature gets +3/+1 until end of turn. Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Aftershock

Destroy target artifact, creature, or land. Aftershock deals 3 damage to you.

Ricochet Trap

If an opponent cast a blue spell this turn, you may pay {R} rather than pay this spell's mana cost.
Change the target of target spell with a single target.

Star Compass

This artifact enters tapped.
{T}: Add one mana of any color that a basic land you control could produce.

Expedite

Target creature gains haste until end of turn.
Draw a card.

Fire Diamond

This artifact enters tapped.
{T}: Add {R}.

Dragon Fodder

Create two 1/1 red Goblin creature tokens.

Crystal Vein

{T}: Add {C}.
{T}, Sacrifice this land: Add {C}{C}.

Volcanic Offering

Destroy target nonbasic land you don't control and target nonbasic land of an opponent's choice you don't control.
Volcanic Offering deals 7 damage to target creature you don't control and 7 damage to target creature of an opponent's choice you don't control.

Brightstone Ritual

Add {R} for each Goblin on the battlefield.

Iron Myr

Dwarven Mine

({T}: Add {R}.)
This land enters tapped unless you control three or more other Mountains.
When this land enters untapped, create a 1/1 red Dwarf creature token.

Renegade Tactics

Target creature can't block this turn.
Draw a card.

Manakin

Heraldic Banner

As this artifact enters, choose a color.
Creatures you control of the chosen color get +1/+0.
{T}: Add one mana of the chosen color.

Ignite Memories

Target player reveals a card at random from their hand. Ignite Memories deals damage to that player equal to that card's mana value.
Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)

Samut's Sprint

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

By Force

Kuldotha Rebirth

As an additional cost to cast this spell, sacrifice an artifact.
Create three 1/1 red Goblin creature tokens.

Accelerate

Stun

Otherworldly Outburst

Target creature gets +1/+0 until end of turn. When that creature dies this turn, create a 3/2 colorless Eldrazi Horror creature token.

Mogg Salvage

If an opponent controls an Island and you control a Mountain, you may cast this spell without paying its mana cost.
Destroy target artifact.

Reckless Charge

Target creature gets +3/+0 and gains haste until end of turn.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Krenko's Command

Reverberate

Copy target instant or sorcery spell. You may choose new targets for the copy.

Millikin

{T}, Mill a card: Add {C}. (To mill a card, put the top card of your library into your graveyard.)

Generator Servant

{T}, Sacrifice this creature: Add {C}{C}. If that mana is spent on a creature spell, it gains haste until end of turn. (That creature can attack and {T} as soon as it comes under your control.)

Kari Zev's Expertise

Gain control of target creature or Vehicle until end of turn. Untap it. It gains haste until end of turn.
You may cast a spell with mana value 2 or less from your hand without paying its mana cost.

Seething Song

Skirk Prospector

Walking Atlas

{T}: You may put a land card from your hand onto the battlefield.

Finale of Promise

You may cast up to one target instant card and/or up to one target sorcery card from your graveyard each with mana value X or less without paying their mana costs. If a spell cast this way would be put into your graveyard, exile it instead. If X is 10 or more, copy each of those spells twice. You may choose new targets for the copies.

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.

Ornithopter of Paradise

Downhill Charge

You may sacrifice a Mountain rather than pay this spell's mana cost.
Target creature gets +X/+0 until end of turn, where X is the number of Mountains you control.

Mishra's Factory

{T}: Add {C}.
{1}: This land becomes a 2/2 Assembly-Worker artifact creature until end of turn. It's still a land.
{T}: Target Assembly-Worker creature gets +1/+1 until end of turn.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice this artifact: Draw a card.

Outnumber

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

Young Pyromancer

Whenever you cast an instant or sorcery spell, create a 1/1 red Elemental creature token.

Emrakul's Hatcher

When this creature enters, create three 0/1 colorless Eldrazi Spawn creature tokens. They have "Sacrifice this token: Add {C}."

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.)

Boiling Blood

Target creature attacks this turn if able.
Draw a card.

Cathartic Reunion

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

Pyroblast

Choose one —
• Counter target spell if it's blue.
• Destroy target permanent if it's blue.

Reliquary Tower

You have no maximum hand size.
{T}: Add {C}.

Fists of Flame

Draw a card. Until end of turn, target creature gains trample and gets +1/+0 for each card you've drawn this turn. (A creature with trample can deal excess combat damage to the player or planeswalker it's attacking.)

Dwarven Ruins

This land enters tapped.
{T}: Add {R}.
{T}, Sacrifice this land: Add {R}{R}.

Forgotten Cave

This land enters tapped.
{T}: Add {R}.
Cycling {R} ({R}, Discard this card: Draw a card.)

Gleeful Demolition

Destroy target artifact. If you controlled that artifact, create three 1/1 red Phyrexian Goblin creature tokens.

Shreds of Sanity

Return up to one target instant card and up to one target sorcery card from your graveyard to your hand, then discard a card. Exile Shreds of Sanity.

Goblin Instigator

When this creature enters, create a 1/1 red Goblin creature token.

Mogg Alarm

You may sacrifice two Mountains rather than pay this spell's mana cost.
Create two 1/1 red Goblin creature tokens.

Firecat Blitz

Create X 1/1 red Elemental Cat creature tokens with haste. Exile them at the beginning of the next end step.
Flashback—{R}{R}, Sacrifice X Mountains. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Goblin Chirurgeon

Sacrifice a Goblin: Regenerate target creature.

Empty the Warrens

Create two 1/1 red Goblin creature tokens.
Storm (When you cast this spell, copy it for each spell cast before it this turn.)

Hordeling Outburst

Create three 1/1 red Goblin creature tokens.

Palladium Myr

Infernal Plunge

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

Battle Hymn

Mizzium Mortars

Mizzium Mortars deals 4 damage to target creature you don't control.
Overload {3}{R}{R}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")