Iymrith, Desert Doom

Flying
Iymrith 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.

Frontier Siege

As this enchantment enters, choose Khans or Dragons.
• Khans — At the beginning of each of your main phases, add {G}{G}.
• Dragons — Whenever a creature you control with flying enters, you may have it fight target creature you don't control.

Savage Lands

This land enters tapped.
{T}: Add {B}, {R}, or {G}.

Stirring Bard

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

Mountain

Dragon's Fire

As an additional cost to cast this spell, you may reveal a Dragon card from your hand or choose a Dragon you control.
Dragon's Fire deals 3 damage to target creature or planeswalker. If you revealed a Dragon card or chose a Dragon as you cast this spell, Dragon's Fire deals damage equal to the power of that card or creature instead.

Opulent Palace

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

Acererak the Archlich

When Acererak enters, if you haven't completed Tomb of Annihilation, return Acererak to its owner's hand and venture into the dungeon.
Whenever Acererak attacks, for each opponent, you create a 2/2 black Zombie creature token unless that player sacrifices a creature of their choice.

Blade of Selves

Equipped creature has myriad. (Whenever it 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.)
Equip {4}

Swamp

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

Scaled Nurturer

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

Mystic Monastery

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

Deathbringer Regent

Flying
When this creature enters, if you cast it from your hand and there are five or more other creatures on the battlefield, destroy all other creatures.

Sea of Clouds

This land enters tapped unless you have two or more opponents.
{T}: Add {W} or {U}.

Nadaar, Selfless Paladin

Vigilance
Whenever Nadaar enters or attacks, venture into the dungeon. (Enter the first room or advance to the next room.)
Other creatures you control get +1/+1 as long as you've completed a dungeon.

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.)

Morphic Pool

This land enters tapped unless you have two or more opponents.
{T}: Add {U} or {B}.

Bladewing the Risen

Flying
When Bladewing enters, you may return target Dragon permanent card from your graveyard to the battlefield.
{B}{R}: Dragon creatures get +1/+1 until end of turn.

Rivaz of the Claw

Menace
{T}: Add two mana in any combination of colors. Spend this mana only to cast Dragon creature spells.
Once during each of your turns, you may cast a Dragon creature spell from your graveyard.
Whenever you cast a Dragon creature spell from your graveyard, it gains "When this creature dies, exile it."

Dragonlord's Servant

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

Black Dragon Gate

This land enters tapped.
As this land enters, choose a color other than black.
{T}: Add {B} or one mana of the chosen color.

Teleportation Circle

At the beginning of your end step, exile up to one target artifact or creature you control, then return that card to the battlefield under its owner's control.

Tiamat

Flying
When Tiamat enters, if you cast it, search your library for up to five Dragon cards not named Tiamat that each have different names, reveal them, put them into your hand, then shuffle.

Arcane Signet

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

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.

Far Traveler

Commander creatures you own have "At the beginning of your end step, exile up to one target tapped creature you control, then return it to the battlefield under its owner's control."

Cave of the Frost Dragon

If you control two or more other lands, this land enters tapped.
{T}: Add {W}.
{4}{W}: This land becomes a 3/4 white Dragon creature with flying until end of turn. It's still a land.

Nahiri's Resolve

Creatures you control get +1/+0 and have haste.
At the beginning of your end step, exile any number of nontoken artifacts and/or creatures you control. Return those cards to the battlefield under their owner's control at the beginning of your next upkeep.

Hoard-Smelter Dragon

Flying
{3}{R}: Destroy target artifact. This creature gets +X/+0 until end of turn, where X is that artifact's mana value.

Exotic Orchard

{T}: Add one mana of any color that a land an opponent controls could produce.

Ganax, Astral Hunter

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

Scourge of Valkas

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

Inherited Envelope

When this artifact enters, the Ring tempts you.
{T}: Add one mana of any color.

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice this artifact: Draw a card.

Loot Dispute

When this enchantment enters, you take the initiative and create a Treasure token.
Whenever you attack the player who has the initiative, create a Treasure token.
Loud Ruckus — Whenever you complete a dungeon, create a 5/5 red Dragon creature token with flying.

Jungle Shrine

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

Dragonspeaker Shaman

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

Goldspan Dragon

Flying, haste
Whenever this creature attacks or becomes the target of a spell, create a Treasure token.
Treasures you control have "{T}, Sacrifice this artifact: Add two mana of any one color."

Smoldering Marsh

({T}: Add {B} or {R}.)
This land enters tapped unless you control two or more basic lands.

Seaside Citadel

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

Forest

Skyline Despot

Flying
When this creature 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.

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 this artifact: 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.

Frontier Bivouac

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

Path to the World Tree

When this enchantment enters, search your library for a basic land card, reveal it, put it into your hand, then shuffle.
{2}{W}{U}{B}{R}{G}, Sacrifice this enchantment: You gain 2 life and draw two cards. Target opponent loses 2 life. This enchantment deals 2 damage to up to one target creature. You create a 2/2 green Bear creature token.

Island

Sarkhan, Soul Aflame

Dragon spells you cast cost {1} less to cast.
Whenever a Dragon you control enters, you may have Sarkhan become a copy of it until end of turn, except its name is Sarkhan, Soul Aflame and it's legendary in addition to its other types.

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.

Dragonborn Champion

Trample
Whenever a source you control deals 5 or more damage to a player, draw a card.

Luxury Suite

This land enters tapped unless you have two or more opponents.
{T}: Add {B} or {R}.

Command Tower

Thrakkus the Butcher

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

Minion of the Mighty

Menace
Pack tactics — Whenever this creature 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.

Triumphant Adventurer

Deathtouch
During your turn, this creature has first strike.
Whenever this creature attacks, venture into the dungeon. (Enter the first room or advance to the next room.)

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.

Crystal Quarry

{T}: Add {C}.
{5}, {T}: Add {W}{U}{B}{R}{G}.

Grand Master of Flowers

As long as Grand Master of Flowers has seven or more loyalty counters on him, he's a 7/7 Dragon God creature with flying and indestructible.
+1: Target creature without first strike, double strike, or vigilance can't attack or block until your next turn.
+1: Search your library and/or graveyard for a card named Monk of the Open Hand, reveal it, and put it into your hand. If you search your library this way, shuffle.

Cascading Cataracts

Indestructible
{T}: Add {C}.
{5}, {T}: Add five mana in any combination of colors.

Blur

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

O-Kagachi, Vengeful Kami

Flying, trample
Whenever O-Kagachi deals combat damage to a player, if that player attacked you during their last turn, exile target nonland permanent that player controls.

Fellwar Stone

Draconic Disciple

{T}: Add one mana of any color.
{7}, {T}, Sacrifice this creature: Create a 5/5 red Dragon creature token with flying.

Adult Gold Dragon

Temple of the Dragon Queen

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

Two-Headed Hellkite

Flying, menace, haste
Whenever this creature attacks, draw two cards.

Gateway Plaza

This land enters tapped.
When this land enters, sacrifice it unless you pay {1}.
{T}: Add one mana of any color.

Hive of the Eye Tyrant

If you control two or more other lands, this land enters tapped.
{T}: Add {B}.
{3}{B}: Until end of turn, this land becomes a 3/3 black Beholder creature with menace and "Whenever this creature attacks, exile target card from defending player's graveyard." It's still a land.

Moonveil Regent

Flying
Whenever you cast a spell, you may discard your hand. If you do, draw a card for each of that spell's colors.
When this creature dies, it deals X damage to any target, where X is the number of colors among permanents you control.

Kodama's Reach

Obsidian Obelisk

This artifact enters tapped.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a multicolored spell.

Dragon's Hoard

Whenever a Dragon you control enters, put a gold counter on this artifact.
{T}, Remove a gold counter from this artifact: Draw a card.
{T}: Add one mana of any color.

Crucible of Fire

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.

Wandering Troubadour

At the beginning of your end step, if you had a land enter the battlefield under your control this turn, venture into the dungeon. (Enter the first room or advance to the next room.)

Carnelian Orb of Dragonkind

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

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.

Red Dragon

Flying
Fire Breath — When this creature enters, it deals 4 damage to each opponent.

Plains

Thunderbreak Regent

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

Cinder Glade

({T}: Add {R} or {G}.)
This land enters tapped unless you control two or more basic lands.

Avenging Hunter

Trample
When this creature enters, you take the initiative.

Migration Path

Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.
Cycling {2} ({2}, Discard this card: Draw a card.)

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.

Gwenna, Eyes of Gaea

{T}: Add two mana in any combination of colors. Spend this mana only to cast creature spells or activate abilities of creature sources.
Whenever you cast a creature spell with power 5 or greater, put a +1/+1 counter on Gwenna and untap it.

Acolyte of Bahamut

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

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.)

Abundant Growth

Enchant land
When this Aura enters, draw a card.
Enchanted land has "{T}: Add one mana of any color."

Mossfire Valley

Dragon's Disciple

As this creature enters, you may reveal a Dragon card from your hand. If you do or if you control a Dragon, this creature enters with a +1/+1 counter on it.
Dragons you control have ward {1}. (Whenever a Dragon you control becomes the target of a spell or ability an opponent controls, counter it unless that player pays {1}.)

Ellywick Tumblestrum

+1: Venture into the dungeon. (Enter the first room or advance to the next room.)
−2: Look at the top six cards of your library. You may reveal a creature card from among them and put it into your hand. If it's legendary, you gain 3 life. Put the rest on the bottom of your library in a random order.
−7: You get an emblem with "Creatures you control have trample and haste and get +2/+2 for each differently named dungeon you've completed."