Klauth, Unrivaled Ancient

Flying, haste
Whenever Klauth, Unrivaled Ancient attacks, add X mana in any combination of colors, where X is the total power of attacking creatures. Spend this mana only to cast spells. Until end of turn, you don't lose this mana as steps and phases end.

Crucible of Fire

Stomping Ground

({T}: Add {R} or {G}.)
As Stomping Ground enters, you may pay 2 life. If you don't, it enters tapped.

Atarka, World Render

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

Temur Ascendancy

Creatures you control have haste.
Whenever a creature you control with power 4 or greater enters, you may draw a card.

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.

Utvara Hellkite

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

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.

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.

Ghostly Flicker

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

Heroic Intervention

Permanents you control gain hexproof and indestructible until end of turn.

Dragonspeaker Shaman

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

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.

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.

Return to Nature

Choose one —
• Destroy target artifact.
• Destroy target enchantment.
• Exile target card from a graveyard.

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.

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.)

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.

Chromatic Lantern

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

Green Sun's Twilight

Reveal the top X plus one cards of your library. Choose a creature card and/or a land card from among them. Put those cards into your hand and the rest on the bottom of your library in a random order. If X is 5 or more, instead put the chosen cards onto the battlefield or into your hand and the rest on the bottom of your library in a random order.

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.

Cryptic Spires

As you create your deck, circle two of the colors below.
Cryptic Spires enters tapped.
{T}: Add one mana of either of the circled colors.

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.)

Thrakkus the Butcher

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

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."

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.

Rejuvenating Springs

Rejuvenating Springs enters tapped unless you have two or more opponents.
{T}: Add {G} or {U}.

Training Grounds

Activated abilities of creatures you control cost {2} less to activate. This effect can't reduce the mana in that cost to less than one mana.

Steam Vents

({T}: Add {U} or {R}.)
As Steam Vents enters, you may pay 2 life. If you don't, it enters tapped.

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.

Command Tower

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

Balefire Dragon

Flying
Whenever Balefire Dragon deals combat damage to a player, it deals that much damage to each creature that player controls.

Draconic Lore

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

Nature's Lore

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

Three Visits

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

Skyshroud Claim

Search your library for up to two Forest cards, put them onto the battlefield, then shuffle.

The Great Henge

This spell costs {X} less to cast, where X is the greatest power among creatures you control.
{T}: Add {G}{G}. You gain 2 life.
Whenever a nontoken creature you control enters, put a +1/+1 counter on it and draw a card.

Kessig Wolf Run

{T}: Add {C}.
{X}{R}{G}, {T}: Target creature gets +X/+0 and gains trample until end of turn.

Conduit of Worlds

You may play lands from your graveyard.
{T}: Choose target nonland permanent card in your graveyard. If you haven't cast a spell this turn, you may cast that card. If you do, you can't cast additional spells this turn. Activate only as a sorcery.

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Spire Garden

Spire Garden enters tapped unless you have two or more opponents.
{T}: Add {R} or {G}.

Niv-Mizzet, Parun

This spell can't be countered.
Flying
Whenever you draw a card, Niv-Mizzet, Parun deals 1 damage to any target.
Whenever a player casts an instant or sorcery spell, you draw a card.

Beast Within

Destroy target permanent. Its controller creates a 3/3 green Beast creature token.

Urza's Incubator

As Urza's Incubator enters, choose a creature type.
Creature spells of the chosen type 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."

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.

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.

Hellkite Tyrant

Flying, trample
Whenever Hellkite Tyrant deals combat damage to a player, gain control of all artifacts that player controls.
At the beginning of your upkeep, if you control twenty or more artifacts, you win the game.

Breeding Pool

({T}: Add {G} or {U}.)
As Breeding Pool enters, you may pay 2 life. If you don't, it enters tapped.

Counterspell

Savage Ventmaw

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

Keiga, the Tide Star

Flying
When Keiga, the Tide Star dies, gain control of target creature.

Farseek

Search your library for a Plains, Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.

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.)

Dragonlord's Servant

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

Terror of the Peaks

Flying
Spells your opponents cast that target Terror of the Peaks cost an additional 3 life to cast.
Whenever another creature you control enters, Terror of the Peaks deals damage equal to that creature's power to any target.

Forest

Kodama's Reach

Rhythm of the Wild

Creature spells you control can't be countered.
Nontoken creatures you control have riot. (They enter with your choice of a +1/+1 counter or haste.)

Shadow in the Warp

The first creature spell you cast each turn costs {2} less to cast.
Whenever an opponent casts their first noncreature spell each turn, Shadow in the Warp deals 2 damage to that player.

Frontier Bivouac

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

Panharmonicon

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

Ketria Triome

({T}: Add {G}, {U}, or {R}.)
Ketria Triome enters tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Capricious Hellraiser

This spell costs {3} less to cast if you have nine or more cards in your graveyard.
Flying
When Capricious Hellraiser enters, exile three cards at random from your graveyard. Choose a noncreature, nonland card from among them and copy it. You may cast the copy without paying its mana cost.

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.

Mountain

Tyvar's Stand

Target creature you control gets +X/+X and gains hexproof and indestructible until end of turn. (A creature with hexproof and indestructible can't be the target of spells or abilities your opponents control. Damage and effects that say "destroy" don't destroy it.)

Blasphemous Act

This spell costs {1} less to cast for each creature on the battlefield.
Blasphemous Act deals 13 damage to each creature.

Cyclonic Rift

Return target nonland permanent you don't control to its owner's hand.
Overload {6}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Rishkar's Expertise

Draw cards equal to the greatest power among creatures you control.
You may cast a spell with mana value 5 or less from your hand without paying its mana cost.

Ancient Copper Dragon

Flying
Whenever Ancient Copper Dragon deals combat damage to a player, roll a d20. You create a number of Treasure tokens equal to the result.

Carnelian Orb of Dragonkind

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

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.

Old Gnawbone

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

Island

Negate

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.