Once Had

Jade Orb of Dragonkind

{T}: Add {G}. When you spend this mana to cast a Dragon creature spell, it enters with an additional +1/+1 counter on it and gains hexproof until your next turn. (It can't be the target of spells or abilities your opponents control.)

Tormenting Voice

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

Miirym, Sentinel Wyrm

Flying, ward {2}
Whenever another nontoken Dragon you control enters, create a token that's a copy of it, except the token isn't legendary.

Rattleclaw Mystic

{T}: Add {G}, {U}, or {R}.
Morph {2} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When Rattleclaw Mystic is turned face up, add {G}{U}{R}.

Racers' Ring

Racers' Ring enters tapped.
{T}: Add {R} or {G}.
{2}{R}{G}, {T}, Sacrifice Racers' Ring: Draw a card.

Path of Ancestry

Path of Ancestry enters tapped.
{T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Dragonspeaker Shaman

Dragon spells you cast cost {2} less to cast.

Acolyte of Bahamut

Commander creatures you own have "The first Dragon spell you cast each turn costs {2} less to cast."

Simic Guildgate

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

Thornwood Falls

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

Starstorm

Starstorm deals X damage to each creature.
Cycling {3} ({3}, Discard this card: Draw a card.)

Nimbleclaw Adept

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

Dissonant Wave

Counter target activated or triggered ability from a noncreature source. (Then exile this card. You may cast the creature later from exile.)

Emerald Dragon

Emerald Dragon // Dissonant Wave

Lurking Green Dragon

Flying
Lurking Green Dragon can't attack unless defending player controls a creature with flying.

Illusionist's Stratagem

Exile up to two target creatures you control, then return those cards to the battlefield under their owner's control.
Draw a card.

Garruk's Uprising

When this enchantment enters, if you control a creature with power 4 or greater, draw a card.
Creatures you control have trample. (Each of those creatures can deal excess combat damage to the player or planeswalker it's attacking.)
Whenever a creature you control with power 4 or greater enters, draw a card.

Swiftwater Cliffs

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

Masked Vandal

Changeling (This card is every creature type.)
When Masked Vandal enters, you may exile a creature card from your graveyard. If you do, exile target artifact or enchantment an opponent controls.

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.

Command Tower

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

Carnelian Orb of Dragonkind

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

Negate

Scaled Nurturer

{T}: Add {G}. When you spend this mana to cast a Dragon creature spell, you gain 2 life.

Terror of Mount Velus

Flying
Double strike (This creature deals both first-strike and regular combat damage.)
When this creature enters, creatures you control gain double strike until end of turn.

Zoological Study

Mill five cards, then return a creature card milled this way to your hand. (Then exile this card. You may cast the artifact later from exile.)

Monster Manual

{1}{G}, {T}: You may put a creature card from your hand onto the battlefield.

Monster Manual // Zoological Study

Island

Fire Diamond

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

Quandrix Campus

Quandrix Campus enters tapped.
{T}: Add {G} or {U}.
{4}, {T}: Scry 1.

Thrakkus the Butcher

Trample
Whenever Thrakkus the Butcher attacks, double the power of each Dragon you control until end of turn.

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.

Llanowar Elves

Seize the Spoils

As an additional cost to cast this spell, discard a card.
Draw two cards and create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Capsizing Wave

Return target creature to its owner's hand. (Then exile this card. You may cast the creature later from exile.)

Sword Coast Serpent

Sword Coast Serpent can't be blocked as long as you've cast a noncreature spell this turn.

Sword Coast Serpent // Capsizing Wave

Displace

Exile up to two target creatures you control, then return those cards to the battlefield under their owner's control.

Dragon Tempest

Whenever a creature you control with flying enters, it gains haste until end of turn.
Whenever a Dragon you control enters, it deals X damage to any target, where X is the number of Dragons you control.

Woodland Stream

Woodland Stream enters tapped.
{T}: Add {G} or {U}.

Relentless Assault

Untap all creatures that attacked this turn. After this main phase, there is an additional combat phase followed by an additional main phase.

Scale Deflection

Put two +1/+1 counters on target creature and untap it. It gains hexproof until end of turn. (Then exile this card. You may cast the creature later from exile.)

Dread Linnorm

Dread Linnorm can't be blocked by creatures with power 3 or less.

Dread Linnorm // Scale Deflection

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.

Avaricious Dragon

Flying
At the beginning of your draw step, draw an additional card.
At the beginning of your end step, discard your hand.

Forest

Korlessa, Scale Singer

You may look at the top card of your library any time.
You may cast Dragon spells from the top of your library.

Decanter of Endless Water

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

Patron of the Arts

When Patron of the Arts enters or dies, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Sky Diamond

Terramorphic Expanse

{T}, Sacrifice Terramorphic Expanse: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Opportunistic Dragon

Flying
When Opportunistic Dragon enters, choose target Human or artifact an opponent controls. For as long as Opportunistic Dragon remains on the battlefield, gain control of that permanent, it loses all abilities, and it can't attack or block.

Moss Diamond

Moss Diamond enters tapped.
{T}: Add {G}.

Distant Melody

Choose a creature type. Draw a card for each permanent you control of that type.

Skanos Dragonheart

Whenever Skanos Dragonheart attacks, it gets +X/+X until end of turn, where X is the greatest power among other Dragons you control and Dragon cards in your graveyard.
Choose a Background (You can have a Background as a second commander.)

Determined Iteration

At the beginning of combat on your turn, populate. The token created this way gains haste. Sacrifice it at the beginning of the next end step. (To populate, create a token that's a copy of a creature token you control.)

Warstorm Surge

Whenever a creature you control enters, it deals damage equal to its power to any target.

Draconic Lore

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

Reflections of Littjara

As Reflections of Littjara enters, choose a creature type.
Whenever you cast a spell of the chosen type, copy that spell. (A copy of a permanent spell becomes a token.)

Dragonlord's Servant

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

Iymrith, Desert Doom

Flying
Iymrith, Desert Doom has ward {4} as long as it's untapped.
Whenever Iymrith deals combat damage to a player, draw a card. Then if you have fewer than three cards in hand, draw cards equal to the difference.

Naturalize

Essence Flux

Exile target creature you control, then return that card to the battlefield under its owner's control. If it's a Spirit, put a +1/+1 counter on it.

Evolving Wilds

{T}, Sacrifice this land: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Shivan Dragon

Flying
{R}: This creature gets +1/+0 until end of turn.

Planar Incision

Exile target artifact or creature, then return it to the battlefield under its owner's control with a +1/+1 counter on it.

Simic Growth Chamber

Simic Growth Chamber enters tapped.
When Simic Growth Chamber enters, return a land you control to its owner's hand.
{T}: Add {G}{U}.

Sol Ring

Orb of Dragonkind

{1}, {T}: Add two mana in any combination of colors. Spend this mana only to cast Dragon spells or activate abilities of Dragons.
{R}, {T}, Sacrifice Orb of Dragonkind: Look at the top seven cards of your library. You may reveal a Dragon card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

You Meet in a Tavern

Choose one —
• Form a Party — Look at the top five cards of your library. You may reveal any number of creature cards from among them and put them into your hand. Put the rest on the bottom of your library in a random order.
• Start a Brawl — Creatures you control get +2/+2 until end of turn.

Gadrak, the Crown-Scourge

Flying
Gadrak, the Crown-Scourge can't attack unless you control four or more artifacts.
At the beginning of your end step, create a Treasure token for each nontoken creature that died this turn. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Blur

Exile target creature you control, then return that card to the battlefield under its owner's control.
Draw a card.

Draconic Muralists

When Draconic Muralists dies, you may search your library for a Dragon card, reveal it, put it into your hand, then shuffle.

Stirring Bard

Defender
When Stirring Bard enters, you take the initiative.
Mantle of Inspiration — {T}: Target creature gains menace and haste until end of turn.

Ghostly Flicker

Exile two target artifacts, creatures, and/or lands you control, then return those cards to the battlefield under your control.

Red Dragon

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

Mountain

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.)

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.

Nature's Lore

Search your library for a Forest card, put that card onto the battlefield, then shuffle.

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.

Rogue's Passage

{T}: Add {C}.
{4}, {T}: Target creature can't be blocked this turn.

Run Away Together

Choose two target creatures controlled by different players. Return those creatures to their owners' hands.

Cultivate

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.