Mountain

Koth, Fire of Resistance

+2: Search your library for a basic Mountain card, reveal it, put it into your hand, then shuffle.
−3: Koth deals damage to target creature equal to the number of Mountains you control.
−7: You get an emblem with "Whenever a Mountain you control enters, this emblem deals 4 damage to any target."

Castle Embereth

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

Goblin Assault

At the beginning of your upkeep, create a 1/1 red Goblin creature token with haste.
Goblin creatures attack each combat if able.

Goblin Warchief

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

Thrill of Possibility

As an additional cost to cast this spell, discard a card.
Draw two cards.

Spawn of Thraxes

Flying
When this creature enters, it deals damage to any target equal to the number of Mountains you control.

Goblin Ringleader

Haste (This creature can attack and {T} as soon as it comes under your control.)
When this creature enters, reveal the top four cards of your library. Put all Goblin cards revealed this way into your hand and the rest on the bottom of your library in any order.

Krenko's Command

Create two 1/1 red Goblin creature tokens.

Red Dragon

Flying
Fire Breath — When this creature enters, it deals 4 damage to each opponent.

Dragon Fodder

Skirk Prospector

Goblin Grenade

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