Dragon Fodder

Create two 1/1 red Goblin creature tokens.

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 Mogg War Marshal enters or dies, create a 1/1 red Goblin creature token.

Ornithopter

Fling

As an additional cost to cast this spell, sacrifice a creature.
Fling deals damage equal to the sacrificed creature's power to any target.

Foundry Street Denizen

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

Goblin Sledder

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

Mountain

Goblin Tomb Raider

As long as you control an artifact, Goblin Tomb Raider gets +1/+0 and has haste.

Voldaren Epicure

When Voldaren Epicure enters, it deals 1 damage to each opponent. Create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this artifact: Draw a card.")

Krenko's Command

Goblin Grenade

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

Great Furnace

Fireblast

You may sacrifice two Mountains rather than pay this spell's mana cost.
Fireblast deals 4 damage to any target.

Goblin Bushwhacker

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

Kuldotha Rebirth

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

Experimental Synthesizer

When Experimental Synthesizer enters or leaves the battlefield, exile the top card of your library. Until end of turn, you may play that card.
{2}{R}, Sacrifice Experimental Synthesizer: Create a 2/2 white Samurai creature token with vigilance. Activate only as a sorcery.