Mugging

Mugging deals 2 damage to target creature. That creature can't block this turn.

Foundry Street Denizen

Whenever another red creature you control enters, Foundry Street Denizen gets +1/+0 until end of turn.

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.

Kiln Fiend

Whenever you cast an instant or sorcery spell, Kiln Fiend gets +3/+0 until end of turn.

Goblin Raider

Dust Corona

Enchant creature
Enchanted creature gets +2/+0 and can't be blocked by creatures with flying.

Scorchwalker

Bloodrush — {1}{R}{R}, Discard Scorchwalker: Target attacking creature gets +5/+1 until end of turn.

Thunder Strike

Target creature gets +2/+0 and gains first strike until end of turn. (It deals combat damage before creatures without first strike.)

Goblin Arsonist

When Goblin Arsonist dies, you may have it deal 1 damage to any target.

Surge of Zeal

Radiance — Target creature and each other creature that shares a color with it gain haste until end of turn.

Crowd's Favor

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Target creature gets +1/+0 and gains first strike until end of turn. (It deals combat damage before creatures without first strike.)

Bull Rush

Target creature gets +2/+0 until end of turn.

Goblin Balloon Brigade

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

Demolish

Goblin Bushwhacker

Kicker {R} (You may pay an additional {R} as you cast this spell.)
When this creature enters, if it was kicked, creatures you control get +1/+0 and gain haste until end of turn.

Madcap Skills

Enchant creature
Enchanted creature gets +3/+0 and has menace.

Blazing Salvo

Blazing Salvo deals 3 damage to target creature unless that creature's controller has Blazing Salvo deal 5 damage to them.