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.

Rolling Thunder

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

Tormenting Voice

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

Dragon Fodder

Create two 1/1 red Goblin creature tokens.

Howling Golem

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

Goblin Motivator

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

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.

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.

Welder Automaton

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

Bombard

Bombard deals 4 damage to target 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.

Havoc Devils

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

Guttersnipe

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

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.)

Demanding Dragon

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

Shock

Goblin Trashmaster

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

Trumpet Blast

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

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.