Runaway Steam-Kin

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

Kiki-Jiki, Mirror Breaker

Haste
{T}: Create a token that's a copy of target nonlegendary creature you control, except it has haste. Sacrifice it at the beginning of the next end step.

Relic Robber

Haste
Whenever this creature deals combat damage to a player, that player creates a 0/1 colorless Goblin Construct artifact creature token with "This token can't block" and "At the beginning of your upkeep, this token deals 1 damage to you."

Boltwave

Boltwave deals 3 damage to each opponent.

Scytheclaw Raptor

Whenever a player casts a spell, if it's not their turn, this creature deals 4 damage to them.

Barbflare Gremlin

First strike, haste
Whenever a player taps a land for mana, if this creature is tapped, that player adds one mana of any type that land produced. Then that land deals 1 damage to that player.

Ankh of Mishra

Whenever a land enters, this artifact deals 2 damage to that land's controller.

Replicating Ring

{T}: Add one mana of any color.
At the beginning of your upkeep, put a night counter on this artifact. Then if it has eight or more night counters on it, remove all of them and create eight colorless snow artifact tokens named Replicated Ring with "{T}: Add one mana of any color."

General Kreat, the Boltbringer

Whenever one or more Goblins you control attack, create a 1/1 red Goblin creature token that's tapped and attacking.
Whenever another creature you control enters, General Kreat deals 1 damage to each opponent.

Arcane Signet

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

Reverberate

Copy target instant or sorcery spell. You may choose new targets for the copy.

Defiler of Instinct

First strike
As an additional cost to cast red permanent spells, you may pay 2 life. Those spells cost {R} less to cast if you paid life this way. This effect reduces only the amount of red mana you pay.
Whenever you cast a red permanent spell, this creature deals 1 damage to any target.

Brash Taunter

Indestructible
Whenever this creature is dealt damage, it deals that much damage to target opponent.
{2}{R}, {T}: This creature fights another target creature.

Twinflame Tyrant

Flying
If a source you control would deal damage to an opponent or a permanent an opponent controls, it deals double that damage instead.

Keldon Firebombers

When this creature enters, each player sacrifices all lands they control except for three.

Tibalt's Trickery

Counter target spell. Choose 1, 2, or 3 at random. Its controller mills that many cards, then exiles cards from the top of their library until they exile a nonland card with a different name than that spell. They may cast that card without paying its mana cost. Then they put the exiled cards on the bottom of their library in a random order.

Tunnel Ignus

Whenever a land enters under an opponent's control, if that player had another land enter the battlefield under their control this turn, this creature deals 3 damage to that player.

Manabarbs

Whenever a player taps a land for mana, this enchantment deals 1 damage to that player.

Dingus Egg

Whenever a land is put into a graveyard from the battlefield, this artifact deals 2 damage to that land's controller.

Impact Tremors

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

Hellkite Tyrant

Flying, trample
Whenever Hellkite Tyrant deals combat damage to a player, gain control of all artifacts that player controls.
At the beginning of your upkeep, if you control twenty or more artifacts, you win the game.

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.

Ruby Medallion

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

Pyroblast

Choose one —
• Counter target spell if it's blue.
• Destroy target permanent if it's blue.

Neheb, the Eternal

Afflict 3 (Whenever this creature becomes blocked, defending player loses 3 life.)
At the beginning of each of your postcombat main phases, add {R} for each 1 life your opponents have lost this turn.

Price of Progress

Price of Progress deals damage to each player equal to twice the number of nonbasic lands that player controls.

Immolation Shaman

Whenever an opponent activates an ability of an artifact, creature, or land that isn't a mana ability, this creature deals 1 damage to that player.
{3}{R}{R}: This creature gets +3/+3 and gains menace until end of turn.

War's Toll

Whenever an opponent taps a land for mana, tap all lands that player controls.
If a creature an opponent controls attacks, all creatures that opponent controls attack if able.

Decanter of Endless Water

You have no maximum hand size.
{T}: Add one mana of any color.

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.

Magebane Lizard

Whenever a player casts a noncreature spell, this creature deals damage to that player equal to the number of noncreature spells they've cast this turn.

Flare of Duplication

You may sacrifice a nontoken red creature rather than pay this spell's mana cost.
Copy target instant or sorcery spell. You may choose new targets for the copy.

Razorkin Needlehead

This creature has first strike during your turn.
Whenever an opponent draws a card, this creature deals 1 damage to them.

Acidic Soil

Acidic Soil deals damage to each player equal to the number of lands they control.

Prisoner's Dilemma

Each opponent secretly chooses silence or snitch, then the choices are revealed. If each opponent chose silence, Prisoner's Dilemma deals 4 damage to each of them. If each opponent chose snitch, Prisoner's Dilemma deals 8 damage to each of them. Otherwise, Prisoner's Dilemma deals 12 damage to each opponent who chose silence.
Flashback {5}{R}{R}

Eidolon of the Great Revel

Whenever a player casts a spell with mana value 3 or less, this creature deals 2 damage to that player.

Sunspine Lynx

Players can't gain life.
Damage can't be prevented.
When this creature enters, it deals damage to each player equal to the number of nonbasic lands that player controls.

Scrawling Crawler

At the beginning of your upkeep, each player draws a card.
Whenever an opponent draws a card, that player loses 1 life.

Nyx Lotus

Nyx Lotus enters tapped.
{T}: Choose a color. Add an amount of mana of that color equal to your devotion to that color. (Your devotion to a color is the number of mana symbols of that color in the mana costs of permanents you control.)

Krenko, Mob Boss

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

Hearthborn Battler

Haste
Whenever a player casts their second spell each turn, this creature deals 2 damage to target opponent.

Obsidian Fireheart

{1}{R}{R}: Put a blaze counter on target land without a blaze counter on it. For as long as that land has a blaze counter on it, it has "At the beginning of your upkeep, this land deals 1 damage to you." (The land continues to burn after this creature has left the battlefield.)

Treasure Nabber

Whenever an opponent taps an artifact for mana, gain control of that artifact until the end of your next turn.

Gleeful Arsonist

Whenever an opponent casts a noncreature spell, this creature deals damage equal to its power to that player.
Undying (When this creature dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it.)

Shattering Spree

Replicate {R} (When you cast this spell, copy it for each time you paid its replicate cost. You may choose new targets for the copies.)
Destroy target artifact.

Insurrection

Untap all creatures and gain control of them until end of turn. They gain haste until end of turn.

Rug of Smothering

Flying
Whenever a player casts a spell, they lose 1 life for each spell they've cast this turn.

Gilded Lotus

Rampaging Ferocidon

Menace
Players can't gain life.
Whenever another creature enters, this creature deals 1 damage to that creature's controller.

Darksteel Ingot

Indestructible (Effects that say "destroy" don't destroy this artifact.)
{T}: Add one mana of any color.

Burning Earth

Whenever a player taps a nonbasic land for mana, this enchantment deals 1 damage to that player.

Red Elemental Blast

Choose one —
• Counter target blue spell.
• Destroy target blue permanent.

Stigma Lasher

Wither (This deals damage to creatures in the form of -1/-1 counters.)
Whenever this creature deals damage to a player, that player can't gain life for the rest of the game.

Disrupt Decorum

Goad all creatures you don't control. (Until your next turn, those creatures attack each combat if able and attack a player other than you if able.)

Mountain

Guttersnipe

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

Vandalblast

Destroy target artifact you don't control.
Overload {4}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Glittering Stockpile

{T}: Add {R}. Put a stash counter on this artifact.
{T}, Sacrifice this artifact: Add X mana of any one color, where X is the number of stash counters on this artifact.

Zo-Zu the Punisher

Whenever a land enters, Zo-Zu deals 2 damage to that land's controller.

Wild Ricochet

You may choose new targets for target instant or sorcery spell. Then copy that spell. You may choose new targets for the copy.

Sulfuric Vortex

At the beginning of each player's upkeep, this enchantment deals 2 damage to that player.
If a player would gain life, that player gains no life instead.

Return the Favor

Spree (Choose one or more additional costs.)
+ {1} — Copy target instant spell, sorcery spell, activated ability, or triggered ability. You may choose new targets for the copy.
+ {1} — Change the target of target spell or ability with a single target.

Solphim, Mayhem Dominus

If a source you control would deal noncombat damage to an opponent or a permanent an opponent controls, it deals double that damage to that player or permanent instead.
{1}{R/P}{R/P}, Discard two cards: Put an indestructible counter on Solphim. ({R/P} can be paid with either {R} or 2 life.)

Sol Ring

Harsh Mentor

Whenever an opponent activates an ability of an artifact, creature, or land on the battlefield, if it isn't a mana ability, this creature deals 2 damage to that player.

Goblin Warrens

{2}{R}, Sacrifice two Goblins: Create three 1/1 red Goblin creature tokens.

Deflecting Swat

If you control a commander, you may cast this spell without paying its mana cost.
You may choose new targets for target spell or ability.

Goblin Bombardment

Sacrifice a creature: This enchantment deals 1 damage to any target.

Vengeful Tracker

Whenever an opponent sacrifices an artifact, this creature deals 2 damage to them.

Chandra's Incinerator

This spell costs {X} less to cast, where X is the total amount of noncombat damage dealt to your opponents this turn.
Trample
Whenever a source you control deals noncombat damage to an opponent, this creature deals that much damage to target creature or planeswalker that player controls.