Plague Myr

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
{T}: Add {C}.

Legion Warboss

Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)
At the beginning of combat on your turn, create a 1/1 red Goblin creature token. That token gains haste until end of turn and attacks this combat if able.

Fire Diamond

Fire Diamond enters tapped.
{T}: Add {R}.

Stun

Target creature can't block this turn.
Draw a card.

Maximize Velocity

Target creature gets +1/+1 and gains haste until end of turn.
Jump-start (You may cast this card from your graveyard by discarding a card in addition to paying its other costs. Then exile this card.)

Battle Hymn

Great Train Heist

Spree (Choose one or more additional costs.)
+ {2}{R} — Untap all creatures you control. If it's your combat phase, there is an additional combat phase after this phase.
+ {2} — Creatures you control get +1/+0 and gain first strike until end of turn.
+ {R} — Choose target opponent. Whenever a creature you control deals combat damage to that player this turn, create a tapped Treasure token.

Seize the Day

Untap target creature. After this main phase, there is an additional combat phase followed by an additional main phase.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Bedlam

Ancestral Anger

Target creature gains trample and gets +X/+0 until end of turn, where X is 1 plus the number of cards named Ancestral Anger in your graveyard. (A creature with trample can deal excess combat damage to the player or planeswalker it's attacking.)
Draw a card.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Crimson Wisps

Target creature becomes red and gains haste until end of turn. (It can attack and {T} this turn.)
Draw a card.

Mass Hysteria

Ruby Medallion

Red spells you cast cost {1} less to cast.

Accelerate

Target creature gains haste until end of turn.
Draw a card.

Loyal Apprentice

Haste
Lieutenant — At the beginning of combat on your turn, if you control your commander, create a 1/1 colorless Thopter artifact creature token with flying. That token gains haste until end of turn.

Dreadmaw's Ire

Until end of turn, target attacking creature gets +2/+2 and gains trample and "Whenever this creature deals combat damage to a player, destroy target artifact that player controls."

Break Through the Line

{R}: Target creature with power 2 or less gains haste until end of turn and can't be blocked this turn.

Ornithopter of Paradise

Expedite

Pashalik Mons

Whenever Pashalik Mons or another Goblin you control dies, Pashalik Mons deals 1 damage to any target.
{3}{R}, Sacrifice a Goblin: Create two 1/1 red Goblin creature tokens.

Krenko, Mob Boss

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

Brightstone Ritual

Add {R} for each Goblin on the battlefield.

Twinflame

Strive — This spell costs {2}{R} more to cast for each target beyond the first.
Choose any number of target creatures you control. For each of them, create a token that's a copy of that creature, except it has haste. Exile those tokens at the beginning of the next end step.

Brute Strength

Target creature gets +3/+1 and gains trample until end of turn. (It can deal excess combat damage to the player or planeswalker it's attacking.)

Young Pyromancer

Whenever you cast an instant or sorcery spell, create a 1/1 red Elemental creature token.

Ardoz, Cobbler of War

Haste
Whenever Ardoz, Cobbler of War or another creature you control enters, that creature gets +2/+0 until end of turn.
{3}{R}: Create a 1/1 red Goblin creature token with haste. Activate only as a sorcery.

Squee, Dubious Monarch

Haste
Whenever Squee, Dubious Monarch attacks, create a 1/1 red Goblin creature token that's tapped and attacking.
You may cast Squee, Dubious Monarch from your graveyard by paying {3}{R} and exiling four other cards from your graveyard rather than paying its mana cost.

Krenko's Command

Create two 1/1 red Goblin creature tokens.

Redcap Gutter-Dweller

Menace
When Redcap Gutter-Dweller enters, create two 1/1 black Rat creature tokens with "This creature can't block."
At the beginning of your upkeep, you may sacrifice another creature. If you do, put a +1/+1 counter on Redcap Gutter-Dweller and exile the top card of your library. You may play that card this turn.

Samut's Sprint

Target creature gets +2/+1 and gains haste until end of turn. Scry 1.

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.

Sol Ring

Rush of Adrenaline

Target creature gets +2/+1 and gains trample until end of turn.

Hordeling Outburst

Create three 1/1 red Goblin creature tokens.

Blazing Crescendo

Target creature gets +3/+1 until end of turn.
Exile the top card of your library. Until the end of your next turn, you may play that card.

Chaos Warp

The owner of target permanent shuffles it into their library, then reveals the top card of their library. If it's a permanent card, they put it onto the battlefield.

Make Mischief

Make Mischief deals 1 damage to any target. Create a 1/1 red Devil creature token. It has "When this creature dies, it deals 1 damage to any target."

Manakin

Battle Cry Goblin

{1}{R}: Goblins you control get +1/+0 and gain haste until end of turn.
Whenever Battle Cry Goblin attacks, if you attacked with creatures with total power 6 or greater this combat, create a 1/1 red Goblin creature token that's tapped and attacking.

Spawning Breath

Spawning Breath deals 1 damage to any target. Create a 0/1 colorless Eldrazi Spawn creature token. It has "Sacrifice this creature: Add {C}."

Might of the Meek

Target creature gains trample until end of turn. It also gets +1/+0 until end of turn if you control a Mouse.
Draw a card.

Sudden Breakthrough

Target creature gets +2/+0 and gains first strike until end of turn.
Create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Otherworldly Outburst

Target creature gets +1/+0 until end of turn. When that creature dies this turn, create a 3/2 colorless Eldrazi Horror creature token.

Flick a Coin

Flick a Coin deals 1 damage to any target. You create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
Draw a card.

Barge In

Target attacking creature gets +2/+2 until end of turn. Each attacking non-Human creature gains trample until end of turn.

Thought Vessel

You have no maximum hand size.
{T}: Add {C}.

Iron Myr

Siege-Gang Commander

When Siege-Gang Commander enters, create three 1/1 red Goblin creature tokens.
{1}{R}, Sacrifice a Goblin: Siege-Gang Commander deals 2 damage to any target.

Monstrous Rage

Target creature gets +2/+0 until end of turn. Create a Monster Role token attached to it. (If you control another Role on it, put that one into the graveyard. Enchanted creature gets +1/+1 and has trample.)

Fists of Flame

Draw a card. Until end of turn, target creature gains trample and gets +1/+0 for each card you've drawn this turn. (A creature with trample can deal excess combat damage to the player or planeswalker it's attacking.)

Dragon Fodder

Beetleback Chief

When Beetleback Chief enters, create two 1/1 red Goblin creature tokens.

Felonious Rage

Target creature you control gets +2/+0 and gains haste until end of turn. When that creature dies this turn, create a 2/2 white and blue Detective creature token.

Traitorous Greed

Gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn. Add two mana of any one color. (The creature can attack and {T} this turn.)

Goblin Traprunner

Whenever Goblin Traprunner attacks, flip three coins. For each flip you win, create a 1/1 red Goblin creature token that's tapped and attacking.

Ancestors' Aid

Zada, Hedron Grinder

Whenever you cast an instant or sorcery spell that targets only Zada, Hedron Grinder, copy that spell for each other creature you control that the spell could target. Each copy targets a different one of those creatures.

Witch's Mark

You may discard a card. If you do, draw two cards.
Create a Wicked Role token attached to up to one target creature you control. (If you control another Role on it, put that one into the graveyard. Enchanted creature gets +1/+1. When this Aura is put into a graveyard, each opponent loses 1 life.)

Storm-Kiln Artist

Storm-Kiln Artist gets +1/+0 for each artifact you control.
Magecraft — Whenever you cast or copy an instant or sorcery spell, create a Treasure token.

Chaotic Strike

Cast this spell only during combat after blockers are declared.
Flip a coin. If you win the flip, target creature gets +1/+1 until end of turn.
Draw a card.

Goblin Instigator

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

Hedron Crawler

{T}: Add {C}. ({C} represents colorless mana.)

Mountain

Reckless Charge

Target creature gets +3/+0 and gains haste until end of turn.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)