Skirk Drill Sergeant

Whenever Skirk Drill Sergeant or another Goblin dies, you may pay {2}{R}. If you do, reveal the top card of your library. If it's a Goblin permanent card, put it onto the battlefield. Otherwise, put it into your graveyard.

Goblin Burrows

{T}: Add {C}.
{1}{R}, {T}: Target Goblin creature gets +2/+0 until end of turn.

Mountain

Goblin Warchief

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

Sparksmith

{T}: Sparksmith deals X damage to target creature and X damage to you, where X is the number of Goblins on the battlefield.

Goblin Taskmaster

{1}{R}: Target Goblin creature gets +1/+0 until end of turn.
Morph {R} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Skirk Marauder

Morph {2}{R} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When Skirk Marauder is turned face up, it deals 2 damage to any target.

Gempalm Incinerator

Cycling {1}{R} ({1}{R}, Discard this card: Draw a card.)
When you cycle Gempalm Incinerator, you may have it deal X damage to target creature, where X is the number of Goblins on the battlefield.

Goblin Piledriver

Protection from blue (This creature can't be blocked, targeted, dealt damage, or enchanted by anything blue.)
Whenever Goblin Piledriver attacks, it gets +2/+0 until end of turn for each other attacking Goblin.

Siege-Gang Commander

When Siege-Gang Commander enters, create three 1/1 red Goblin creature tokens.
{1}{R}, Sacrifice a Goblin: Siege-Gang Commander deals 2 damage to any target.

Embermage Goblin

When Embermage Goblin enters, you may search your library for a card named Embermage Goblin, reveal it, put it into your hand, then shuffle.
{T}: Embermage Goblin deals 1 damage to any target.