Dwarven Mine

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

Skirk Prospector

Goblin Chirurgeon

Sacrifice a Goblin: Regenerate target creature.

Impulsive Pilferer

When Impulsive Pilferer dies, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
Encore {3}{R} ({3}{R}, Exile this card from your graveyard: For each opponent, create a token copy that attacks that opponent this turn if able. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.)

Goblin Anarchomancer

Each spell you cast that's red or green costs {1} less to cast.

Hobgoblin Captain

Pack tactics — Whenever Hobgoblin Captain attacks, if you attacked with creatures with total power 6 or greater this combat, Hobgoblin Captain gains first strike until end of turn.

Panic Spellbomb

{T}, Sacrifice Panic Spellbomb: Target creature can't block this turn.
When Panic Spellbomb is put into a graveyard from the battlefield, you may pay {R}. If you do, draw a card.

Goblin Matron

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

Goblin Javelineer

Haste
Whenever Goblin Javelineer becomes blocked, it deals 1 damage to target creature blocking it.

Pyrite Spellbomb

{R}, Sacrifice Pyrite Spellbomb: It deals 2 damage to any target.
{1}, Sacrifice Pyrite Spellbomb: Draw a card.

Forest

Rummaging Goblin

Beetleback Chief

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

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Jund Hackblade

As long as you control another multicolored permanent, Jund Hackblade gets +1/+1 and has haste.

Forgotten Cave

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

Mountain

Tin Street Hooligan

When Tin Street Hooligan enters, if {G} was spent to cast it, destroy target artifact.