Outlaws' Merriment

At the beginning of your upkeep, choose one at random. Create a red and white creature token with those characteristics.
• 3/1 Human Warrior with trample and haste.
• 2/1 Human Cleric with lifelink and haste.
• 1/2 Human Rogue with haste and "When this creature enters, it deals 1 damage to any target."

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.

Goblin Instigator

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

Sacred Foundry

({T}: Add {R} or {W}.)
As Sacred Foundry enters, you may pay 2 life. If you don't, it enters tapped.

Light Up the Stage

Spectacle {R} (You may cast this spell for its spectacle cost rather than its mana cost if an opponent lost life this turn.)
Exile the top two cards of your library. Until the end of your next turn, you may play those cards.

Plains

Boros Charm

Choose one —
• Boros Charm deals 4 damage to target player or planeswalker.
• Permanents you control gain indestructible until end of turn.
• Target creature gains double strike until end of turn.

Chained to the Rocks

Enchant Mountain you control
When Chained to the Rocks enters, exile target creature an opponent controls until Chained to the Rocks leaves the battlefield. (That creature returns under its owner's control.)

Collateral Damage

As an additional cost to cast this spell, sacrifice a creature.
Collateral Damage deals 3 damage to any target.

Impact Tremors

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

Angelic Exaltation

Whenever a creature you control attacks alone, it gets +X/+X until end of turn, where X is the number of creatures you control.

Ajani's Welcome

Whenever a creature you control enters, you gain 1 life.

Divine Visitation

If one or more creature tokens would be created under your control, that many 4/4 white Angel creature tokens with flying and vigilance are created instead.

Clifftop Retreat

Clifftop Retreat enters tapped unless you control a Mountain or a Plains.
{T}: Add {R} or {W}.

Mountain

Krenko, Tin Street Kingpin

Whenever Krenko, Tin Street Kingpin attacks, put a +1/+1 counter on it, then create a number of 1/1 red Goblin creature tokens equal to Krenko's power.