Mountain

Purphoros, God of the Forge

Indestructible
As long as your devotion to red is less than five, Purphoros isn't a creature.
Whenever another creature enters the battlefield under your control, Purphoros deals 2 damage to each opponent.
{2}{R}: Creatures you control get +1/+0 until end of turn.

Goblin Warrens

{2}{R}, Sacrifice two Goblins: Create three 1/1 red Goblin creature tokens.

Iron Myr

Skullclamp

Equipped creature gets +1/-1.
Whenever equipped creature dies, draw two cards.
Equip {1}

Dragon Fodder

Create two 1/1 red Goblin creature tokens.

Goblin Warchief

Goblin spells you cast cost {1} less to cast.
Goblins you control have haste.

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.)

Cavern of Souls

As Cavern of Souls enters the battlefield, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type, and that spell can't be countered.

Goblin Recruiter

When Goblin Recruiter enters the battlefield, search your library for any number of Goblin cards, reveal them, then shuffle and put those cards on top in any order.

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.

Sol Ring

Muxus, Goblin Grandee

When Muxus, Goblin Grandee enters the battlefield, reveal the top six cards of your library. Put all Goblin creature cards with mana value 5 or less from among them onto the battlefield and the rest on the bottom of your library in a random order.
Whenever Muxus attacks, it gets +1/+1 until end of turn for each other Goblin you control.

Coldsteel Heart

Coldsteel Heart enters the battlefield tapped.
As Coldsteel Heart enters the battlefield, choose a color.
{T}: Add one mana of the chosen color.

Fire Diamond

Fire Diamond enters the battlefield tapped.
{T}: Add {R}.

Krenko, Mob Boss

{T}: Create X 1/1 red Goblin creature tokens, where X is the number of Goblins you control.