Runaway Steam-Kin

Whenever you cast a red spell, if Runaway Steam-Kin has fewer than three +1/+1 counters on it, put a +1/+1 counter on Runaway Steam-Kin.
Remove three +1/+1 counters from Runaway Steam-Kin: Add {R}{R}{R}.

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.

Samut's Sprint

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

Expedite

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

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.

Song of Totentanz

Create X 1/1 black Rat creature tokens with "This creature can't block." Creatures you control gain haste until end of turn.

Krenko, Mob Boss

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

Skirk Prospector

Krenko's Command

Create two 1/1 red Goblin creature tokens.

Renegade Tactics

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

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.)

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.)

Dragon Fodder

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.

Crimson Wisps

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

Seething Song

Mirrorwing Dragon

Flying
Whenever a player casts an instant or sorcery spell that targets only Mirrorwing Dragon, that player copies that spell for each other creature they control that the spell could target. Each copy targets a different one of those creatures.

Brightstone Ritual

Add {R} for each Goblin on the battlefield.

Heat Shimmer

Create a token that's a copy of target creature, except it has haste and "At the beginning of the end step, exile this permanent."

Dualcaster Mage

Flash
When Dualcaster Mage enters, copy target instant or sorcery spell. You may choose new targets for the copy.

Rile

Rile deals 1 damage to target creature you control. That creature gains trample until end of turn.
Draw a card.

Strionic Resonator

{2}, {T}: Copy target triggered ability you control. You may choose new targets for the copy. (A triggered ability uses the words "when," "whenever," or "at.")

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.

Goblin Chirurgeon

Sacrifice a Goblin: Regenerate target creature.

Young Pyromancer

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

Titan's Strength

Target creature gets +3/+1 until end of turn. Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Empty the Warrens

Create two 1/1 red Goblin creature tokens.
Storm (When you cast this spell, copy it for each spell cast before it this turn.)

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.")

Guttersnipe

Whenever you cast an instant or sorcery spell, this creature deals 2 damage to each opponent.

Accelerate

Krark, the Thumbless

Whenever you cast an instant or sorcery spell, flip a coin. If you lose the flip, return that spell to its owner's hand. If you win the flip, copy that spell, and you may choose new targets for the copy.
Partner (You can have two commanders if both have partner.)

Blood Moon

Inner Fire

Unleash Fury

Double the power of target creature until end of turn.

Boiling Blood

Target creature attacks this turn if able.
Draw a card.

Battle Hymn

Stun

Goblin Warchief

Goblin spells you cast cost {1} less to cast.
Goblins you control have haste.

Display of Power

This spell can't be copied.
Copy any number of target instant and/or sorcery spells. You may choose new targets for the copies.

Hordeling Outburst

Create three 1/1 red Goblin creature tokens.

Goblin Matron

When Goblin Matron enters, you may search your library for a Goblin card, reveal that card, put it into your hand, then shuffle.

Kick in the Door

Put a +1/+1 counter on target creature. That creature gains haste until end of turn and can't be blocked by Walls this turn. Venture into the dungeon. (Enter the first room or advance to the next room.)

Dreadhorde Arcanist

Trample
Whenever Dreadhorde Arcanist attacks, you may cast target instant or sorcery card with mana value less than or equal to Dreadhorde Arcanist's power from your graveyard without paying its mana cost. If that spell would be put into your graveyard, exile it instead.

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.)

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.

Goblin Instigator

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

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.

Goblinslide

Whenever you cast a noncreature spell, you may pay {1}. If you do, create a 1/1 red Goblin creature token with haste.

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.

Underworld Breach

Each nonland card in your graveyard has escape. The escape cost is equal to the card's mana cost plus exile three other cards from your graveyard. (You may cast cards from your graveyard for their escape cost.)
At the beginning of the end step, sacrifice Underworld Breach.