Act of Treason

Gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn. (It can attack and {T} this turn.)

Volley Veteran

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

Eager Construct

When Eager Construct enters, each player may scry 1. (To scry 1, look at the top card of your library, then you may put that card on the bottom.)

Goblin

Dragon Fodder

Create two 1/1 red Goblin creature tokens.

Bombard

Bombard deals 4 damage to target creature.

Guttersnipe

Whenever you cast an instant or sorcery spell, Guttersnipe deals 2 damage to each opponent.

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.

Mountain

Seismic Elemental

When Seismic Elemental enters, creatures without flying can't block this turn.

Havoc Devils

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)

Goblin Trashmaster

Other Goblins you control get +1/+1.
Sacrifice a Goblin: Destroy target artifact.

Demanding Dragon

Flying
When Demanding Dragon enters, it deals 5 damage to target opponent unless that player sacrifices a creature.

Captivating Crew

{3}{R}: Gain control of target creature an opponent controls until end of turn. Untap that creature. It gains haste until end of turn. Activate only as a sorcery.

Goblin Motivator

{T}: Target creature gains haste until end of turn. (It can attack and {T} this turn.)

Trumpet Blast

Attacking creatures get +2/+0 until end of turn.

Howling Golem

Whenever Howling Golem attacks or blocks, each player draws a card.

Tormenting Voice

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

Goblin Instigator

When Goblin Instigator enters, create a 1/1 red Goblin creature token.

Rolling Thunder

Rolling Thunder deals X damage divided as you choose among any number of targets.

Welder Automaton

{3}{R}: Welder Automaton deals 1 damage to each opponent.

Shock

Goblin Goliath

When Goblin Goliath enters, create a number of 1/1 red Goblin creature tokens equal to the number of opponents you have.
{3}{R}, {T}: If a source you control would deal damage to an opponent this turn, it deals double that damage to that player instead.

Shivan Dragon

Flying (This creature can't be blocked except by creatures with flying or reach.)
{R}: Shivan Dragon gets +1/+0 until end of turn.