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.

Krenko, Mob Boss

{T}: Create X 1/1 red Goblin creature tokens, where X is the number of Goblins you control.

Impact Tremors

Whenever a creature you control enters, this enchantment deals 1 damage to each opponent.

Blood Moon

Magus of the Moon

Mountain

Goblin Caves

Enchant land
As long as enchanted land is a basic Mountain, Goblin creatures get +0/+2.

Red Elemental Blast

Choose one —
• Counter target blue spell.
• Destroy target blue permanent.