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.

Elemental Bond

Whenever a creature with power 3 or greater enters the battlefield under your control, draw a card.

Lathliss, Dragon Queen

Flying
Whenever another nontoken Dragon enters the battlefield under your control, create a 5/5 red Dragon creature token with flying.
{1}{R}: Dragons you control get +1/+0 until end of turn.

Drakuseth, Maw of Flames

Flying
Whenever Drakuseth, Maw of Flames attacks, it deals 4 damage to any target and 3 damage to each of up to two other targets.

Drumhunter

At the beginning of your end step, if you control a creature with power 5 or greater, you may draw a card.
{T}: Add {C}.

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.

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.

Rugged Highlands

Rugged Highlands enters the battlefield tapped.
When Rugged Highlands enters the battlefield, you gain 1 life.
{T}: Add {R} or {G}.

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.)

Talisman of Impulse

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

Harbinger of the Hunt

Flying
{2}{R}: Harbinger of the Hunt deals 1 damage to each creature without flying.
{2}{G}: Harbinger of the Hunt deals 1 damage to each other creature with flying.

Hunter's Prowess

Until end of turn, target creature gets +3/+3 and gains trample and "Whenever this creature deals combat damage to a player, draw that many cards."

Tyrant's Familiar

Flying, haste
Lieutenant — As long as you control your commander, Tyrant's Familiar gets +2/+2 and has "Whenever Tyrant's Familiar attacks, it deals 7 damage to target creature defending player controls."

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.

Carnelian Orb of Dragonkind

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

Mountain

Commander's Sphere

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

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.)

Beast Within

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

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.

Return of the Wildspeaker

Choose one —
• Draw cards equal to the greatest power among non-Human creatures you control.
• Non-Human creatures you control get +3/+3 until end of turn.

Thundermaw Hellkite

Flying
Haste (This creature can attack and {T} as soon as it comes under your control.)
When Thundermaw Hellkite enters the battlefield, it deals 1 damage to each creature with flying your opponents control. Tap those creatures.

Dragonlord's Servant

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

Frontier Siege

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

Scaled Nurturer

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

Fire Diamond

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

Crucible of Fire

Demanding Dragon

Flying
When Demanding Dragon enters the battlefield, it deals 5 damage to target opponent unless that player sacrifices a creature.

Terramorphic Expanse

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

Runehorn Hellkite

Flying
{5}{R}, Exile Runehorn Hellkite from your graveyard: Each player discards their hand, then draws seven cards.

Foe-Razer Regent

Flying
When Foe-Razer Regent enters the battlefield, you may have it fight target creature you don't control.
Whenever a creature you control fights, put two +1/+1 counters on it at the beginning of the next end step.

Mordant Dragon

Flying
{1}{R}: Mordant Dragon gets +1/+0 until end of turn.
Whenever Mordant Dragon deals combat damage to a player, you may have it deal that much damage to target creature that player controls.

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.

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control.)
Equip {1}

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.)

Primal Might

Target creature you control gets +X/+X until end of turn. Then it fights up to one target creature you don't control.

Utvara Hellkite

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

Temple of Abandon

Temple of Abandon enters the battlefield tapped.
When Temple of Abandon enters the battlefield, scry 1.
{T}: Add {R} or {G}.

Dream Pillager

Flying
Whenever Dream Pillager deals combat damage to a player, exile that many cards from the top of your library. Until end of turn, you may cast spells from among those exiled cards.

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.

Evolving Wilds

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

Sweltering Suns

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

Chain Reaction

Chain Reaction deals X damage to each creature, where X is the number of creatures on the battlefield.

Kazandu Refuge

Kazandu Refuge enters the battlefield tapped.
When Kazandu Refuge enters the battlefield, you gain 1 life.
{T}: Add {R} or {G}.

Thrakkus the Butcher

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

Cinder Glade

({T}: Add {R} or {G}.)
Cinder Glade enters the battlefield tapped unless you control two or more basic lands.

Hunter's Insight

Choose target creature you control. Whenever that creature deals combat damage to a player or planeswalker this turn, draw that many cards.

Sarkhan, the Dragonspeaker

+1: Until end of turn, Sarkhan, the Dragonspeaker becomes a legendary 4/4 red Dragon creature with flying, indestructible, and haste. (He doesn't lose loyalty while he's not a planeswalker.)
−3: Sarkhan, the Dragonspeaker deals 4 damage to target creature.
−6: You get an emblem with "At the beginning of your draw step, draw two additional cards" and "At the beginning of your end step, discard your hand."

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.)

Dragon Mage

Flying
Whenever Dragon Mage deals combat damage to a player, each player discards their hand, then draws seven cards.

Magmaquake

Magmaquake deals X damage to each creature without flying and each planeswalker.

Acolyte of Bahamut

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

Flameblast Dragon

Flying
Whenever Flameblast Dragon attacks, you may pay {X}{R}. If you do, Flameblast Dragon deals X damage to any target.

Backdraft Hellkite

Flying
Whenever Backdraft Hellkite attacks, each instant and sorcery card in your graveyard gains flashback until end of turn. The flashback cost is equal to its mana cost.

Livaan, Cultist of Tiamat

Whenever you cast a noncreature spell, target creature gets +X/+0 until end of turn, where X is that spell's mana value.
Choose a Background (You can have a Background as a second commander.)

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.

Steel Hellkite

Flying
{2}: Steel Hellkite gets +1/+0 until end of turn.
{X}: Destroy each nonland permanent with mana value X whose controller was dealt combat damage by Steel Hellkite this turn. Activate only once each turn.

Draconic Disciple

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

Harmonize

Spit Flame

Spit Flame deals 4 damage to target creature.
Whenever a Dragon enters the battlefield under your control, you may pay {R}. If you do, return Spit Flame from your graveyard to your hand.

Dragonspeaker Shaman

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

Sol Ring

Game Trail

As Game Trail enters the battlefield, you may reveal a Mountain or Forest card from your hand. If you don't, Game Trail enters the battlefield tapped.
{T}: Add {R} or {G}.

Fires of Yavimaya

Creatures you control have haste.
Sacrifice Fires of Yavimaya: Target creature gets +2/+2 until end of turn.

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.

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.

Verix Bladewing

Kicker {3} (You may pay an additional {3} as you cast this spell.)
Flying
When Verix Bladewing enters the battlefield, if it was kicked, create Karox Bladewing, a legendary 4/4 red Dragon creature token with flying.

Return to Nature

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

Command Tower

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

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.

Arcane Signet

Atarka, World Render

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

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.

Shivan Oasis

Shivan Oasis enters the battlefield tapped.
{T}: Add {R} or {G}.

Forest

Hoard-Smelter Dragon

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

Vandalblast

Destroy target artifact you don't control.
Overload {4}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")