Dragonlord's Servant

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

Reckless Barbarian

Sacrifice Reckless Barbarian: Add {R}{R}.

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.

Body of Research

Create a 0/0 green and blue Fractal creature token. Put X +1/+1 counters on it, where X is the number of cards in your library.

Skyline Despot

Flying
When Skyline Despot enters the battlefield, 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.

Mirror Image

You may have Mirror Image enter the battlefield as a copy of a creature you control.

Double Major

Copy target creature spell you control, except it isn't legendary if the spell is legendary. (A copy of a creature spell becomes a token.)

Savage Ventmaw

Flying
Whenever Savage Ventmaw attacks, add {R}{R}{R}{G}{G}{G}. Until end of turn, you don't lose this mana as steps and phases end.

Astral Dragon

Flying
Project Image — When Astral Dragon enters the battlefield, create two tokens that are copies of target noncreature permanent, except they're 3/3 Dragon creatures in addition to their other types, and they have flying.

Genesis Ultimatum

Look at the top five cards of your library. Put any number of permanent cards from among them onto the battlefield and the rest into your hand. Exile Genesis Ultimatum.

Helm of the Host

At the beginning of combat on your turn, create a token that's a copy of equipped creature, except the token isn't legendary. That token gains haste.
Equip {5}

Search for Tomorrow

Search your library for a basic land card, put it onto the battlefield, then shuffle.
Suspend 2—{G} (Rather than cast this card from your hand, you may pay {G} and exile it with two time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost.)

Dragon Tempest

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

Azusa, Lost but Seeking

You may play two additional lands on each of your turns.

Voidwalk

Exile target creature. Return it to the battlefield under its owner's control at the beginning of the next end step.
Cipher (Then you may exile this spell card encoded on a creature you control. Whenever that creature deals combat damage to a player, its controller may cast a copy of the encoded card without paying its mana cost.)

Jade Orb of Dragonkind

{T}: Add {G}. When you spend this mana to cast a Dragon creature spell, it enters the battlefield 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.)

Arcbound Whelp

Flying
{R}: Arcbound Whelp gets +1/+0 until end of turn.
Modular 2 (This creature enters the battlefield with two +1/+1 counters on it. When it dies, you may put its +1/+1 counters on target artifact creature.)

Goblin Anarchomancer

Each spell you cast that's red or green costs {1} less to cast.

Dragonspeaker Shaman

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

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.)

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

Panharmonicon

If an artifact or creature entering the battlefield causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Ganax, Astral Hunter

Flying
Whenever Ganax, Astral Hunter or another Dragon enters the battlefield under your control, 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.)

Command Tower

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

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.

Kodama's Reach

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.

Jaheira, Friend of the Forest

Tokens you control have "{T}: Add {G}."
Choose a Background (You can have a Background as a second commander.)

Traverse the Outlands

Search your library for up to X basic land cards, where X is the greatest power among creatures you control. Put those cards onto the battlefield tapped, then shuffle.

Frontier Bivouac

Frontier Bivouac enters the battlefield tapped.
{T}: Add {G}, {U}, or {R}.

Dragon's Hoard

Whenever a Dragon enters the battlefield under your control, 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.

Sarkhan Unbroken

+1: Draw a card, then add one mana of any color.
−2: Create a 4/4 red Dragon creature token with flying.
−8: Search your library for any number of Dragon creature cards, put them onto the battlefield, then shuffle.

Terramorphic Expanse

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

Temple of the Dragon Queen

As Temple of the Dragon Queen enters the battlefield, you may reveal a Dragon card from your hand. Temple of the Dragon Queen enters the battlefield tapped unless you revealed a Dragon card this way or you control a Dragon.
As Temple of the Dragon Queen enters the battlefield, choose a color.
{T}: Add one mana of the chosen color.

Miirym, Sentinel Wyrm

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

Glasspool Shore

Glasspool Shore enters the battlefield tapped.
{T}: Add {U}.

Glasspool Mimic

You may have Glasspool Mimic enter the battlefield as a copy of a creature you control, except it's a Shapeshifter Rogue in addition to its other types.

Glasspool Mimic // Glasspool Shore

Island

Scaled Nurturer

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

Evolving Wilds

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

Second Harvest

For each token you control, create a token that's a copy of that permanent.

Acolyte of Bahamut

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

Shamanic Revelation

Draw a card for each creature you control.
Ferocious — You gain 4 life for each creature you control with power 4 or greater.

Haven of the Spirit Dragon

{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a Dragon creature spell.
{2}, {T}, Sacrifice Haven of the Spirit Dragon: Return target Dragon creature card or Ugin planeswalker card from your graveyard to your hand.

Shifting Shadow

Enchant creature
Enchanted creature has haste and "At the beginning of your upkeep, destroy this creature. Reveal cards from the top of your library until you reveal a creature card. Put that card onto the battlefield and attach Shifting Shadow to it, then put all other cards revealed this way on the bottom of your library in a random order."

Firkraag, Cunning Instigator

Flying, haste
Whenever one or more Dragons you control attack an opponent, goad target creature that player controls.
Whenever a creature deals combat damage to one of your opponents, if that creature had to attack this combat, you put a +1/+1 counter on Firkraag, Cunning Instigator and you draw a card.

Ghostly Flicker

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

Defense of the Heart

At the beginning of your upkeep, if an opponent controls three or more creatures, sacrifice Defense of the Heart, search your library for up to two creature cards, put those cards onto the battlefield, then shuffle.

Chromatic Lantern

Lands you control have "{T}: Add one mana of any color."
{T}: Add one mana of any color.

Path of Ancestry

Path of Ancestry enters the battlefield 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.)

Minion of the Mighty

Menace
Pack tactics — Whenever Minion of the Mighty attacks, if you attacked with creatures with total power 6 or greater this combat, you may put a Dragon creature card from your hand onto the battlefield tapped and attacking.

Forest

Sol Ring

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.

Earthquake Dragon

This spell costs {X} less to cast, where X is the total mana value of Dragons you control.
Flying, trample
{2}{G}, Sacrifice a land: Return Earthquake Dragon from your graveyard to your hand.

Garruk's Uprising

When Garruk's Uprising enters the battlefield, if you control a creature with power 4 or greater, draw a card.
Creatures you control have trample. (They can deal excess combat damage to the player or planeswalker they're attacking.)
Whenever a creature with power 4 or greater enters the battlefield under your control, draw a card.

Scourge of Valkas

Flying
Whenever Scourge of Valkas or another Dragon enters the battlefield under your control, 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.

Dragon Broodmother

Flying
At the beginning of each upkeep, create a 1/1 red and green Dragon creature token with flying and devour 2. (As the token enters the battlefield, you may sacrifice any number of creatures. It enters the battlefield with twice that many +1/+1 counters on it.)

Atarka, World Render

Flying, trample
Whenever a Dragon you control attacks, it gains double strike until end of turn.

Mountain

Displace

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

Helm of Awakening

Thrakkus the Butcher

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

Draconic Muralists

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

Carnelian Orb of Dragonkind

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

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.

Vesuvan Drifter

Flying
You may look at the top card of your library any time.
At the beginning of each combat, you may reveal the top card of your library. If you reveal a creature card this way, Vesuvan Drifter becomes a copy of that card until end of turn, except it has flying.

Crucible of Fire

Doors of Durin

Whenever you attack, scry 2, then you may reveal the top card of your library. If it's a creature card, put it onto the battlefield tapped and attacking. Until your next turn, it gains trample if you control a Dwarf and hexproof if you control an Elf.

Cloud Key

As Cloud Key enters the battlefield, choose artifact, creature, enchantment, instant, or sorcery.
Spells you cast of the chosen type cost {1} less to cast.

Explore

You may play an additional land this turn.
Draw a card.

Wrathful Red Dragon

Flying
Whenever a Dragon you control is dealt damage, it deals that much damage to any target that isn't a Dragon.

Rampant Growth

Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.