Hordeling Outburst

Create three 1/1 red Goblin creature tokens.

Goblin Instigator

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

Lava Coil

Lava Coil deals 4 damage to target creature. If that creature would die this turn, exile it instead.

Dragon Fodder

Create two 1/1 red Goblin creature tokens.

Descent of the Dragons

Destroy any number of target creatures. For each creature destroyed this way, its controller creates a 4/4 red Dragon creature token with flying.

Abrade

Choose one —
• Abrade deals 3 damage to target creature.
• Destroy target artifact.

Impact Tremors

Whenever a creature you control enters, Impact Tremors deals 1 damage to each opponent.

Mountain

Scorching Dragonfire

Scorching Dragonfire deals 3 damage to target creature or planeswalker. If that creature or planeswalker would die this turn, exile it instead.

Purphoros, God of the Forge

Indestructible
As long as your devotion to red is less than five, Purphoros isn't a creature.
Whenever another creature you control enters, Purphoros deals 2 damage to each opponent.
{2}{R}: Creatures you control get +1/+0 until end of turn.

Pia Nalaar

When Pia Nalaar enters, create a 1/1 colorless Thopter artifact creature token with flying.
{1}{R}: Target artifact creature gets +1/+0 until end of turn.
{1}, Sacrifice an artifact: Target creature can't block this turn.

Pia and Kiran Nalaar

When Pia and Kiran Nalaar enters, create two 1/1 colorless Thopter artifact creature tokens with flying.
{2}{R}, Sacrifice an artifact: Pia and Kiran Nalaar deals 2 damage to any target.