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.)

Chromatic Lantern

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

Kindred Discovery

As Kindred Discovery enters, choose a creature type.
Whenever a creature you control of the chosen type enters or attacks, draw a card.

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.

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.

Herald's Horn

As Herald's Horn enters, choose a creature type.
Creature spells you cast of the chosen type cost {1} less to cast.
At the beginning of your upkeep, look at the top card of your library. If it's a creature card of the chosen type, you may reveal it and put it into your hand.

Ancient Silver Dragon

Flying
Whenever Ancient Silver Dragon deals combat damage to a player, roll a d20. Draw cards equal to the result. You have no maximum hand size for the rest of the game.

Evolving Wilds

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

Forest

Blighted Woodland

{T}: Add {C}.
{3}{G}, {T}, Sacrifice Blighted Woodland: Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Sneak Attack

{R}: You may put a creature card from your hand onto the battlefield. That creature gains haste. Sacrifice the creature at the beginning of the next end step.

Talisman of Curiosity

{T}: Add {C}.
{T}: Add {G} or {U}. Talisman of Curiosity deals 1 damage to you.

Exotic Orchard

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

Red Dragon

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

Thrakkus the Butcher

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

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.

Mosswort Bridge

Hideaway 4 (When this land enters, look at the top four cards of your library, exile one face down, then put the rest on the bottom in a random order.)
Mosswort Bridge enters tapped.
{T}: Add {G}.
{G}, {T}: You may play the exiled card without paying its mana cost if creatures you control have total power 10 or greater.

Chaos Warp

The owner of target permanent shuffles it into their library, then reveals the top card of their library. If it's a permanent card, they put it onto the battlefield.

Old Gnawbone

Flying
Whenever a creature you control deals combat damage to a player, create that many Treasure tokens.

Fellwar Stone

Draconic Muralists

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

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.

Astral Dragon

Flying
Project Image — When Astral Dragon enters, 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.

Sarkhan, Fireblood

+1: You may discard a card. If you do, draw a card.
+1: Add two mana in any combination of colors. Spend this mana only to cast Dragon spells.
−7: Create four 5/5 red Dragon creature tokens with flying.

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.)

Goldspan Dragon

Flying, haste
Whenever Goldspan Dragon 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."

Goblin Anarchomancer

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

Lithoform Engine

{2}, {T}: Copy target activated or triggered ability you control. You may choose new targets for the copy.
{3}, {T}: Copy target instant or sorcery spell you control. You may choose new targets for the copy.
{4}, {T}: Copy target permanent spell you control. (The copy becomes a token.)

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}.

Opal Palace

{T}: Add {C}.
{1}, {T}: Add one mana of any color in your commander's color identity. If you spend this mana to cast your commander, it enters with a number of additional +1/+1 counters on it equal to the number of times it's been cast from the command zone this game.

Fabled Passage

{T}, Sacrifice Fabled Passage: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle. Then if you control four or more lands, untap that land.

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.

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.

Command Tower

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

Simic Signet

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.

Dragonlord's Servant

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

Sakashima of a Thousand Faces

You may have Sakashima of a Thousand Faces enter as a copy of another creature you control, except it has Sakashima of a Thousand Faces's other abilities.
The "legend rule" doesn't apply to permanents you control.
Partner (You can have two commanders if both have partner.)

Changeling Berserker

Changeling (This card is every creature type.)
Haste
Champion a creature (When this enters, sacrifice it unless you exile another creature you control. When this leaves the battlefield, that card returns to the battlefield.)

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.

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.)

Progenitor Mimic

You may have Progenitor Mimic enter as a copy of any creature on the battlefield, except it has "At the beginning of your upkeep, if this creature isn't a token, create a token that's a copy of this creature."

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.

Sarkhan's Triumph

Search your library for a Dragon creature card, reveal it, put it into your hand, then shuffle.

Dack's Duplicate

You may have Dack's Duplicate enter as a copy of any creature on the battlefield, except it has haste and dethrone. (Whenever it attacks the player with the most life or tied for most life, put a +1/+1 counter on it.)

Parallel Lives

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead.

Ancient Bronze Dragon

Flying
Whenever Ancient Bronze Dragon deals combat damage to a player, roll a d20. When you do, put X +1/+1 counters on each of up to two target creatures, where X is the result.

Temple of Abandon

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {R} or {G}.

Urza's Incubator

As Urza's Incubator enters, choose a creature type.
Creature spells of the chosen type cost {2} less to cast.

Temple of Mystery

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {G} or {U}.

Izzet Boilerworks

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

Fire-Lit Thicket

{T}: Add {C}.
{R/G}, {T}: Add {R}{R}, {R}{G}, or {G}{G}.

Kindred Summons

Choose a creature type. Reveal cards from the top of your library until you reveal X creature cards of the chosen type, where X is the number of creatures you control of that type. Put those cards onto the battlefield, then shuffle the rest of the revealed cards into your library.

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.

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.

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.

Sol Ring

Cryptic Gateway

Tap two untapped creatures you control: You may put a creature card from your hand that shares a creature type with each creature tapped this way onto the battlefield.

Nogi, Draco-Zealot

Dragon spells you cast cost {1} less to cast.
Whenever Nogi, Draco-Zealot attacks, if you control three or more Dragons, until end of turn, Nogi becomes a Dragon with base power and toughness 5/5 and gains flying.

Flooded Grove

{T}: Add {C}.
{G/U}, {T}: Add {G}{G}, {G}{U}, or {U}{U}.

Acolyte of Bahamut

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

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.)

Reckless Barbarian

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

Talisman of Impulse

{T}: Add {C}.
{T}: Add {R} or {G}. Talisman of Impulse deals 1 damage to you.

Moritte of the Frost

Changeling (This card is every creature type.)
You may have Moritte of the Frost enter as a copy of a permanent you control, except it's legendary and snow in addition to its other types and, if it's a creature, it enters with two additional +1/+1 counters on it and has changeling.

Cascade Bluffs

{T}: Add {C}.
{U/R}, {T}: Add {U}{U}, {U}{R}, or {R}{R}.

Gruul Turf

Gruul Turf enters tapped.
When Gruul Turf enters, return a land you control to its owner's hand.
{T}: Add {R}{G}.

Mountain

Arcane Signet

Adrix and Nev, Twincasters

Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
If one or more tokens would be created under your control, twice that many of those tokens are created instead.

Strionic Resonator

{2}, {T}: Copy target triggered ability you control. You may choose new targets for the copy. (A triggered ability uses the words "when," "whenever," or "at.")

Temple of Epiphany

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {U} or {R}.

Gruul Signet

Terramorphic Expanse

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

Izzet Signet

Temple of the False God

{T}: Add {C}{C}. Activate only if you control five or more lands.

Doubling Season

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead.
If an effect would put one or more counters on a permanent you control, it puts twice that many of those counters on that permanent instead.

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.

Frontier Bivouac

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

Machine God's Effigy

You may have Machine God's Effigy enter as a copy of any creature on the battlefield, except it's an artifact and it has "{T}: Add {U}." (It's not a creature.)
{T}: Add {U}.

Cursed Mirror

{T}: Add {R}.
As Cursed Mirror enters, you may have it become a copy of any creature on the battlefield until end of turn, except it has haste.

Kindred Charge

Choose a creature type. For each creature you control of the chosen type, create a token that's a copy of that creature. Those tokens gain haste. Exile them at the beginning of the next end step.

Island

Talisman of Creativity

{T}: Add {C}.
{T}: Add {U} or {R}. Talisman of Creativity deals 1 damage to you.

Ash Barrens

{T}: Add {C}.
Basic landcycling {1} ({1}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

Spark Double

You may have Spark Double enter as a copy of a creature or planeswalker you control, except it enters with an additional +1/+1 counter on it if it's a creature, it enters with an additional loyalty counter on it if it's a planeswalker, and it isn't legendary.

Dragonspeaker Shaman

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

Commander's Sphere

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