Act of Treason

Gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn. (It can attack and {T} this turn.)

Hordeling Outburst

Create three 1/1 red Goblin creature tokens.

Tibalt, Rakish Instigator

Your opponents can't gain life.
−2: Create a 1/1 red Devil creature token with "When this creature dies, it deals 1 damage to any target."

Humble Defector

{T}: Draw two cards. Target opponent gains control of Humble Defector. Activate only during your turn.

Etali, Primal Storm

Whenever Etali, Primal Storm attacks, exile the top card of each player's library, then you may cast any number of spells from among those cards without paying their mana costs.

Battle-Rattle Shaman

At the beginning of combat on your turn, you may have target creature get +2/+0 until end of turn.

Goblin Smuggler

Haste (This creature can attack and {T} as soon as it comes under your control.)
{T}: Another target creature with power 2 or less can't be blocked this turn.

Boggart Brute

Menace (This creature can't be blocked except by two or more creatures.)

Goblin Instigator

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

Bolt Hound

Haste (This creature can attack and {T} as soon as it comes under your control.)
Whenever Bolt Hound attacks, other creatures you control get +1/+0 until end of turn.

Tormenting Voice

As an additional cost to cast this spell, discard a card.
Draw two cards.

Brazen Wolves

Whenever Brazen Wolves attacks, it gets +2/+0 until end of turn.

Torbran, Thane of Red Fell

If a red source you control would deal damage to an opponent or a permanent an opponent controls, it deals that much damage plus 2 instead.

Lightning Strike

Lightning Strike deals 3 damage to any target.

Howling Golem

Whenever Howling Golem attacks or blocks, each player draws a card.

Flametongue Kavu

When Flametongue Kavu enters, it deals 4 damage to target creature.

Mountain

Goblin Motivator

{T}: Target creature gains haste until end of turn. (It can attack and {T} this turn.)

Borderland Marauder

Whenever Borderland Marauder attacks, it gets +2/+0 until end of turn.

Chandra's Outrage

Chandra's Outrage deals 4 damage to target creature and 2 damage to that creature's controller.

Embermaw Hellion

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
If another red source you control would deal damage to a permanent or player, it deals that much damage plus 1 to that permanent or player instead.

Red Dragon

Flying
Fire Breath — When Red Dragon enters, it deals 4 damage to each opponent.

Shock

Shivan Dragon

Flying (This creature can't be blocked except by creatures with flying or reach.)
{R}: Shivan Dragon gets +1/+0 until end of turn.