Firebreathing

Enchant creature
{R}: Enchanted creature gets +1/+0 until end of turn.

Tarfire

Chandra Nalaar

+1: Chandra Nalaar deals 1 damage to target player or planeswalker.
−X: Chandra Nalaar deals X damage to target creature.
−8: Chandra Nalaar deals 10 damage to target player or planeswalker and each creature that player or that planeswalker's controller controls.

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.

Flamekin Brawler

{R}: Flamekin Brawler gets +1/+0 until end of turn.

Goblin Fireslinger

{T}: Goblin Fireslinger deals 1 damage to target player or planeswalker.

Shock

Rings of Brighthearth

Whenever you activate an ability, if it isn't a mana ability, you may pay {2}. If you do, copy that ability. You may choose new targets for the copy.

Curse of the Pierced Heart

Enchant player
At the beginning of enchanted player's upkeep, Curse of the Pierced Heart deals 1 damage to that player or a planeswalker that player controls.

Prodigal Pyromancer

{T}: Prodigal Pyromancer deals 1 damage to any target.

Lava Axe

Lava Axe deals 5 damage to target player or planeswalker.

Mountain

Raging Goblin

Haste (This creature can attack and {T} as soon as it comes under your control.)

Mogg Mob

Sacrifice Mogg Mob: It deals 3 damage divided as you choose among one, two, or three targets.

Heat Shimmer

Create a token that's a copy of target creature, except it has haste and "At the beginning of the end step, exile this permanent."

Reckless Pyrosurfer

Haste
Landfall — Whenever a land you control enters, Reckless Pyrosurfer gains battle cry until end of turn. (Whenever this creature attacks, each other attacking creature gets +1/+0 until end of turn. Each instance of battle cry triggers separately.)

Slagstorm

Choose one —
• Slagstorm deals 3 damage to each creature.
• Slagstorm deals 3 damage to each player.

Goblin Sky Raider

Flying (This creature can't be blocked except by creatures with flying or reach.)

Red Sun's Zenith

Red Sun's Zenith deals X damage to any target. If a creature dealt damage this way would die this turn, exile it instead. Shuffle Red Sun's Zenith into its owner's library.

Smelted Chargebug

Menace
When Smelted Chargebug enters, you get {E}{E} (two energy counters).
Whenever Smelted Chargebug attacks, you may pay {E}. If you do, another target attacking creature gets +1/+0 and gains menace until end of turn.

Flameblast Dragon

Flying
Whenever Flameblast Dragon attacks, you may pay {X}{R}. If you do, Flameblast Dragon deals X damage to any target.

Incinerate

Incinerate deals 3 damage to any target. A creature dealt damage this way can't be regenerated this turn.