Chain Reaction

Chain Reaction deals X damage to each creature, where X is the number of creatures on the battlefield.

Reckless One

Haste
Reckless One's power and toughness are each equal to the number of Goblins on the battlefield.

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

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.

Creatures you control have haste. (They can attack and {T} as soon as they come under your control.)

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

Flash
When this creature enters, you may have it deal damage to target creature or planeswalker equal to the number of Goblins you control.

Defender
{T}: This creature deals 1 damage to each player.

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

Sacrifice a creature: This enchantment deals 1 damage to any target.

Wither (This deals damage to creatures in the form of -1/-1 counters.)

Create three 1/1 red Goblin creature tokens.