Plains

Ganax, Astral Hunter

Flying
Whenever Ganax, Astral Hunter or another Dragon you control enters, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
Choose a Background (You can have a Background as a second commander.)

Palladium Myr

Demanding Dragon

Flying
When Demanding Dragon enters, it deals 5 damage to target opponent unless that player sacrifices a creature of their choice.

Peculiar Lighthouse

Peculiar Lighthouse enters tapped unless a player has 13 or less life.
{T}: Add {U} or {R}.

Captivating Cave

{T}: Add {C}.
{1}, {T}: Add one mana of any color.
{4}, {T}, Sacrifice Captivating Cave: Put two +1/+1 counters on target creature. Activate only as a sorcery.

Mountain

Knollspine Dragon

Flying
When Knollspine Dragon enters, you may discard your hand and draw cards equal to the damage dealt to target opponent this turn.

Lapis Orb of Dragonkind

{T}: Add {U}. When you spend this mana to cast a Dragon creature spell, scry 2. (Look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Dragon's Hoard

Whenever a Dragon you control enters, put a gold counter on Dragon's Hoard.
{T}, Remove a gold counter from Dragon's Hoard: Draw a card.
{T}: Add one mana of any color.

Niv-Mizzet, the Firemind

Flying
Whenever you draw a card, Niv-Mizzet, the Firemind deals 1 damage to any target.
{T}: Draw a card.

Forktail Sweep

Forktail Sweep deals 1 damage to each creature you don't control. (Then exile this card. You may cast the creature later from exile.)

Fang Dragon

Fang Dragon // Forktail Sweep

Realm-Scorcher Hellkite

Bargain (You may sacrifice an artifact, enchantment, or token as you cast this spell.)
Flying, haste
When Realm-Scorcher Hellkite enters, if it was bargained, add four mana in any combination of colors.
{1}{R}: Realm-Scorcher Hellkite deals 1 damage to any target.

Boros Guildgate

This land enters tapped.
{T}: Add {R} or {W}.

Steel Hellkite

Flying
{2}: This creature gets +1/+0 until end of turn.
{X}: Destroy each nonland permanent with mana value X whose controller was dealt combat damage by this creature this turn. Activate only once each turn.

Wind-Scarred Crag

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {R} or {W}.

Unknown Shores

{T}: Add {C}.
{1}, {T}: Add one mana of any color.

Livaan, Cultist of Tiamat

Whenever you cast a noncreature spell, target creature gets +X/+0 until end of turn, where X is that spell's mana value.
Choose a Background (You can have a Background as a second commander.)

Utvara Hellkite

Flying
Whenever a Dragon you control attacks, create a 6/6 red Dragon creature token with flying.

Hedron Archive

{T}: Add {C}{C}.
{2}, {T}, Sacrifice this artifact: Draw two cards.

Tranquil Cove

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {W} or {U}.

Gold Myr

Drakuseth, Maw of Flames

Flying
Whenever Drakuseth attacks, it deals 4 damage to any target and 3 damage to each of up to two other targets.

Renari, Merchant of Marvels

You may cast Dragon spells and artifact spells as though they had flash.
Choose a Background (You can have a Background as a second commander.)

Thunderbreak Regent

Flying
Whenever a Dragon you control becomes the target of a spell or ability an opponent controls, Thunderbreak Regent deals 3 damage to that player.

Abandoned Campground

Abandoned Campground enters tapped unless a player has 13 or less life.
{T}: Add {W} or {U}.

Hellkite Charger

Flying, haste
Whenever Hellkite Charger attacks, you may pay {5}{R}{R}. If you do, untap all attacking creatures and after this phase, there is an additional combat phase.

Unbreakable Formation

Creatures you control gain indestructible until end of turn.
Addendum — If you cast this spell during your main phase, put a +1/+1 counter on each of those creatures and they gain vigilance until end of turn.

Sand Augury

Scry 1, then draw a card. (Then exile this card. You may cast the creature later from exile.)

Young Blue Dragon

Young Blue Dragon // Sand Augury

Island

Baral, Chief of Compliance

Instant and sorcery spells you cast cost {1} less to cast.
Whenever a spell or ability you control counters a spell, you may draw a card. If you do, discard a card.

Skyline Despot

Flying
When Skyline Despot enters, you become the monarch.
At the beginning of your upkeep, if you're the monarch, create a 5/5 red Dragon creature token with flying.

Inspiring Leader

Commander creatures you own have "Creature tokens you control get +2/+2."

Monastery Siege

As Monastery Siege enters, choose Khans or Dragons.
• Khans — At the beginning of your draw step, draw an additional card, then discard a card.
• Dragons — Spells your opponents cast that target you or a permanent you control cost {2} more to cast.

Glorybringer

Flying, haste
You may exert Glorybringer as it attacks. When you do, it deals 4 damage to target non-Dragon creature an opponent controls. (An exerted creature won't untap during your next untap step.)

Restless Bivouac

Restless Bivouac enters tapped.
{T}: Add {R} or {W}.
{1}{R}{W}: Restless Bivouac becomes a 2/2 red and white Ox creature until end of turn. It's still a land.
Whenever Restless Bivouac attacks, put a +1/+1 counter on target creature you control.

Quicksilver Fisher

Flying
When Quicksilver Fisher enters, draw a card, then discard a card.

Lozhan, Dragons' Legacy

Flying
Whenever you cast an Adventure or Dragon spell, Lozhan, Dragons' Legacy deals damage equal to that spell's mana value to any target that isn't a commander.

Zurgo and Ojutai

Flying, haste
Zurgo and Ojutai has hexproof as long as it entered this turn.
Whenever one or more Dragons you control deal combat damage to a player or battle, look at the top three cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order. You may return one of those Dragons to its owner's hand.

Oculus Whelp

Flying
As long as you control a transformed permanent, Oculus Whelp has "When Oculus Whelp dies, draw a card."

Pseudodragon Familiar

Flying
{2}{U}: Target creature gains flying until end of turn.

Skyship Stalker

Flying
{R}: Skyship Stalker gets +1/+0 until end of turn.
{R}: Skyship Stalker gains first strike until end of turn.
{R}: Skyship Stalker gains haste until end of turn.

Rapacious Dragon

Flying
When this creature enters, create two Treasure tokens. (They're artifacts with "{T}, Sacrifice this token: Add one mana of any color.")

Bathe in Gold

Create a Treasure token. (Then exile this card. You may cast the creature later from exile.)

Young Red Dragon

Young Red Dragon // Bathe in Gold

Breath Weapon

Breath Weapon deals 2 damage to each non-Dragon creature.

Sol Ring

Izzet Guildgate

This land enters tapped.
{T}: Add {U} or {R}.

Scourge of Valkas

Flying
Whenever Scourge of Valkas or another Dragon you control enters, it deals X damage to any target, where X is the number of Dragons you control.
{R}: Scourge of Valkas gets +1/+0 until end of turn.

Dragonmaster Outcast

At the beginning of your upkeep, if you control six or more lands, create a 5/5 red Dragon creature token with flying.

Warmonger Hellkite

Flying
All creatures attack each combat if able.
{1}{R}: Attacking creatures get +1/+0 until end of turn.

Curiosity

Enchant creature
Whenever enchanted creature deals damage to an opponent, you may draw a card.

Tiamat's Fanatics

Haste
Myriad (Whenever this creature attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)

Restless Spire

Restless Spire enters tapped.
{T}: Add {U} or {R}.
{U}{R}: Until end of turn, Restless Spire becomes a 2/1 blue and red Elemental creature with "During your turn, this creature has first strike." It's still a land.
Whenever Restless Spire attacks, scry 1.

Raucous Carnival

Raucous Carnival enters tapped unless a player has 13 or less life.
{T}: Add {R} or {W}.

Hypersonic Dragon

Flying, haste
You may cast sorcery spells as though they had flash. (You may cast them any time you could cast an instant.)

Irenicus's Vile Duplication

Create a token that's a copy of target creature you control, except the token has flying and it isn't legendary.

Experimental Augury

Look at the top three cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order. Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Draconic Lore

This spell costs {2} less to cast if you control a Dragon.
Draw three cards.

Archive Dragon

Flying
Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
When Archive Dragon enters, scry 2.

Lathliss, Dragon Queen

Flying
Whenever another nontoken Dragon you control enters, create a 5/5 red Dragon creature token with flying.
{1}{R}: Dragons you control get +1/+0 until end of turn.

Reliquary Tower

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

Mocking Sprite

Flying
Instant and sorcery spells you cast cost {1} less to cast.

Sarkhan the Masterless

Whenever a creature attacks you or a planeswalker you control, each Dragon you control deals 1 damage to that creature.
+1: Until end of turn, each planeswalker you control becomes a 4/4 red Dragon creature and gains flying.
−3: Create a 4/4 red Dragon creature token with flying.

Manalith

Skybridge Towers

Skybridge Towers enters tapped.
{T}: Add {W} or {U}.
{2}{W}{U}, {T}, Sacrifice Skybridge Towers: Draw a card.

Coastal Piracy

Whenever a creature you control deals combat damage to an opponent, you may draw a card.

Nimbleclaw Adept

Bigby's Hand — {T}: Untap two other target permanents. Activate only as a sorcery and only once each turn.

Weave Fate

Bonehoard Dracosaur

Flying, first strike
At the beginning of your upkeep, exile the top two cards of your library. You may play them this turn. If you exiled a land card this way, create a 3/1 red Dinosaur creature token. If you exiled a nonland card this way, create a Treasure token.

Sprite Dragon

Flying, haste
Whenever you cast a noncreature spell, put a +1/+1 counter on Sprite Dragon.

Crystal Barricade

Defender (This creature can't attack.)
You have hexproof. (You can't be the target of spells or abilities your opponents control.)
Prevent all noncombat damage that would be dealt to other creatures you control.

Desert of the Fervent

Desert of the Fervent enters tapped.
{T}: Add {R}.
Cycling {1}{R} ({1}{R}, Discard this card: Draw a card.)

Thriving Heath

Thriving Heath enters tapped. As it enters, choose a color other than white.
{T}: Add {W} or one mana of the chosen color.

Archwing Dragon

Flying, haste
At the beginning of the end step, return Archwing Dragon to its owner's hand.

Azorius Chancery

Azorius Chancery enters tapped.
When Azorius Chancery enters, return a land you control to its owner's hand.
{T}: Add {W}{U}.

Candlekeep Sage

Commander creatures you own have "When this creature enters or leaves the battlefield, draw a card."

Phyrexian Dragon Engine

Double strike
When Phyrexian Dragon Engine enters from your graveyard, you may discard your hand. If you do, draw three cards.
Unearth {3}{R}{R}
(Melds with Mishra, Claimed by Gix.)

Avatar of Slaughter

All creatures have double strike and attack each combat if able.

Carnelian Orb of Dragonkind

{T}: Add {R}. If that mana is spent on a Dragon creature spell, it gains haste until end of turn.

Crystal Grotto

When Crystal Grotto enters, scry 1.
{T}: Add {C}.
{1}, {T}: Add one mana of any color.

Port Town

As Port Town enters, you may reveal a Plains or Island card from your hand. If you don't, Port Town enters tapped.
{T}: Add {W} or {U}.

Decanter of Endless Water

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

Fury of the Horde

You may exile two red cards from your hand rather than pay this spell's mana cost.
Untap all creatures that attacked this turn. After this main phase, there is an additional combat phase followed by an additional main phase.

Turnabout

Choose artifact, creature, or land. Tap all untapped permanents of the chosen type target player controls, or untap all tapped permanents of that type that player controls.

Izzet Boilerworks

Izzet Boilerworks enters tapped.
When Izzet Boilerworks enters, return a land you control to its owner's hand.
{T}: Add {U}{R}.

Izzet Signet

Velomachus Lorehold

Flying, vigilance, haste
Whenever Velomachus Lorehold attacks, look at the top seven cards of your library. You may cast an instant or sorcery spell with mana value less than or equal to Velomachus Lorehold's power from among them without paying its mana cost. Put the rest on the bottom of your library in a random order.

Needle Spires

Needle Spires enters tapped.
{T}: Add {R} or {W}.
{2}{R}{W}: Needle Spires becomes a 2/1 red and white Elemental creature with double strike until end of turn. It's still a land.

Flaming Fist

Commander creatures you own have "Whenever this creature attacks, it gains double strike until end of turn."