Goblin Researcher

When Goblin Researcher enters, exile the top card of your library. During any turn you attacked with Goblin Researcher, you may play that card.

Ardoz, Cobbler of War

Haste
Whenever Ardoz, Cobbler of War or another creature you control enters, that creature gets +2/+0 until end of turn.
{3}{R}: Create a 1/1 red Goblin creature token with haste. Activate only as a sorcery.

Dragon Fodder

Create two 1/1 red Goblin creature tokens.

Torch Courier

Haste
Sacrifice Torch Courier: Another target creature gains haste until end of turn.

Goblin Grenade

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

Rummaging Goblin

Goblin Rabblemaster

Other Goblin creatures you control attack each combat if able.
At the beginning of combat on your turn, create a 1/1 red Goblin creature token with haste.
Whenever Goblin Rabblemaster attacks, it gets +1/+0 until end of turn for each other attacking Goblin.

Mountain

Outnumber

Outnumber deals damage to target creature equal to the number of creatures you control.

Goblin Rally

Create four 1/1 red Goblin creature tokens.

Burn Bright

Creatures you control get +2/+0 until end of turn.

Thriving Bluff

Thriving Bluff enters tapped. As it enters, choose a color other than red.
{T}: Add {R} or one mana of the chosen color.

Hordeling Outburst

Create three 1/1 red Goblin creature tokens.

Volley Veteran

When this creature enters, it deals damage to target creature an opponent controls equal to the number of Goblins you control.