Goblin Chieftain

Haste (This creature can attack and {T} as soon as it comes under your control.)
Other Goblin creatures you control get +1/+1 and have haste.

Earthquake

Earthquake deals X damage to each creature without flying and each player.

Fireball

This spell costs {1} more to cast for each target beyond the first.
Fireball deals X damage divided evenly, rounded down, among any number of targets.

Umezawa's Jitte

Whenever equipped creature deals combat damage, put two charge counters on Umezawa's Jitte.
Remove a charge counter from Umezawa's Jitte: Choose one —
• Equipped creature gets +2/+2 until end of turn.
• Target creature gets -1/-1 until end of turn.
• You gain 2 life.
Equip {2}

Mountain

Mogg Raider

Sacrifice a Goblin: Target creature gets +1/+1 until end of turn.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Boil

Goblin Bombardment

Sacrifice a creature: Goblin Bombardment deals 1 damage to any target.

Zada's Commando

First strike
Cohort — {T}, Tap an untapped Ally you control: Zada's Commando deals 1 damage to target opponent or planeswalker.

Furnace of Rath

If a source would deal damage to a permanent or player, it deals double that damage to that permanent or player instead.

Ball Lightning

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
Haste (This creature can attack and {T} as soon as it comes under your control.)
At the beginning of the end step, sacrifice this creature.

Rampaging Ferocidon

Menace
Players can't gain life.
Whenever another creature enters, Rampaging Ferocidon deals 1 damage to that creature's controller.

Rigging Runner

First strike
Raid — Rigging Runner enters with a +1/+1 counter on it if you attacked this turn.