Springleaf Drum

{T}, Tap an untapped creature you control: Add one mana of any color.

Mountain

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 the battlefield or dies, create a 1/1 red Goblin creature token.

Foundry Street Denizen

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

Mob Justice

Mob Justice deals damage to target player or planeswalker equal to the number of creatures you control.

Dragon Fodder

Create two 1/1 red Goblin creature tokens.

Chromatic Star

{1}, {T}, Sacrifice Chromatic Star: Add one mana of any color.
When Chromatic Star is put into a graveyard from the battlefield, draw a card.

Skirk Prospector

Goblin Matron

When Goblin Matron enters the battlefield, you may search your library for a Goblin card, reveal that card, put it into your hand, then shuffle.

Distant Melody

Choose a creature type. Draw a card for each permanent you control of that type.

Reckless Impulse

Exile the top two cards of your library. Until the end of your next turn, you may play those cards.

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.

Brightstone Ritual

Add {R} for each Goblin on the battlefield.

Kuldotha Rebirth

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