Chain Lightning

Chain Lightning deals 3 damage to any target. Then that player or that permanent's controller may pay {R}{R}. If the player does, they may copy this spell and may choose a new target for that copy.

Goblin King

Other Goblins get +1/+1 and have mountainwalk.

Mountain

Goblin Marshal

Echo {4}{R}{R} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)
When Goblin Marshal enters or dies, create two 1/1 red Goblin creature tokens.

Goblin Balloon Brigade

{R}: Goblin Balloon Brigade gains flying until end of turn.

Goblin Hero

Lava Axe

Lava Axe deals 5 damage to target player or planeswalker.

Goblin Grenade

As an additional cost to cast this spell, sacrifice a Goblin.
Goblin Grenade deals 5 damage to any target.

Goblin Berserker

Parch

Choose one —
• Parch deals 2 damage to any target.
• Parch deals 4 damage to target blue creature.

Goblin War Buggy

Haste
Echo {1}{R} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)

Shock

Goblin Medics

Whenever Goblin Medics becomes tapped, it deals 1 damage to any target.

Goblin Gardener

When Goblin Gardener dies, destroy target land.

Goblin Matron

When Goblin Matron enters, you may search your library for a Goblin card, reveal that card, put it into your hand, then shuffle.