Have

Mountain

Arid Mesa

{T}, Pay 1 life, Sacrifice Arid Mesa: Search your library for a Mountain or Plains card, put it onto the battlefield, then shuffle.

Castle Embereth

Castle Embereth enters the battlefield tapped unless you control a Mountain.
{T}: Add {R}.
{1}{R}{R}, {T}: Creatures you control get +1/+0 until end of turn.

Foundry Street Denizen

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

Scalding Tarn

{T}, Pay 1 life, Sacrifice Scalding Tarn: Search your library for an Island or Mountain card, put it onto the battlefield, then shuffle.

Prismatic Vista

{T}, Pay 1 life, Sacrifice Prismatic Vista: Search your library for a basic land card, put it onto the battlefield, then shuffle.

Bloodstained Mire

{T}, Pay 1 life, Sacrifice Bloodstained Mire: Search your library for a Swamp or Mountain card, put it onto the battlefield, then shuffle.

Kuldotha Rebirth

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

Wooded Foothills

{T}, Pay 1 life, Sacrifice Wooded Foothills: Search your library for a Mountain or Forest card, put it onto the battlefield, then shuffle.

Mishra's Bauble

{T}, Sacrifice Mishra's Bauble: Look at the top card of target player's library. Draw a card at the beginning of the next turn's upkeep.

Goblin Grenade

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

Gleeful Demolition

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

Ornithopter

Shrapnel Blast

As an additional cost to cast this spell, sacrifice an artifact.
Shrapnel Blast deals 5 damage to any target.

Goblin Bushwhacker

Kicker {R} (You may pay an additional {R} as you cast this spell.)
When Goblin Bushwhacker enters the battlefield, if it was kicked, creatures you control get +1/+0 and gain haste until end of turn.

Signal Pest

Battle cry (Whenever this creature attacks, each other attacking creature gets +1/+0 until end of turn.)
Signal Pest can't be blocked except by creatures with flying or reach.

Memnite

Ramunap Ruins

{T}: Add {C}.
{T}, Pay 1 life: Add {R}.
{2}{R}{R}, {T}, Sacrifice a Desert: Ramunap Ruins deals 2 damage to each opponent.

Reckless Bushwhacker

Surge {1}{R} (You may cast this spell for its surge cost if you or a teammate has cast another spell this turn.)
Haste
When Reckless Bushwhacker enters the battlefield, if its surge cost was paid, other creatures you control get +1/+0 and gain haste until end of turn.

Goblin Guide

Haste
Whenever Goblin Guide attacks, defending player reveals the top card of their library. If it's a land card, that player puts it into their hand.