Helga, Skittish Seer

Whenever you cast a creature spell with mana value 4 or greater, you draw a card, gain 1 life, and put a +1/+1 counter on Helga.
{T}: Add X mana of any one color, where X is Helga's power. Spend this mana only to cast creature spells with mana value 4 or greater or creature spells with {X} in their mana costs.

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.

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.

Utvara Hellkite

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

Zurgo and Ojutai

Flying, haste
Zurgo and Ojutai has hexproof as long as it entered this turn.
Whenever one or more Dragons you control deal combat damage to a player or battle, look at the top three cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order. You may return one of those Dragons to its owner's hand.

Withstand Death

Target creature gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it. If its toughness is 0 or less, it's still put into its owner's graveyard.)

Arena of Glory

This land enters tapped unless you control a Mountain.
{T}: Add {R}.
{R}, {T}, Exert this land: Add {R}{R}. If that mana is spent on a creature spell, it gains haste until end of turn. (An exerted permanent won't untap during your next untap step.)

Green Sun's Zenith

Search your library for a green creature card with mana value X or less, put it onto the battlefield, then shuffle. Shuffle Green Sun's Zenith into its owner's library.

Dragonlord Silumgar

Flying, deathtouch
When Dragonlord Silumgar enters, gain control of target creature or planeswalker for as long as you control Dragonlord Silumgar.

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.

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 this land: Return target Dragon creature card or Ugin planeswalker card from your graveyard to your hand.

Path of Ancestry

This land enters 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.)

Sol Ring

Carnelian Orb of Dragonkind

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

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.

Dragonlord Dromoka

This spell can't be countered.
Flying, lifelink
Your opponents can't cast spells during your turn.

Unbreakable Formation

Creatures you control gain indestructible until end of turn.
Addendum — If you cast this spell during your main phase, put a +1/+1 counter on each of those creatures and they gain vigilance until end of turn.

Forest

Plains

Secluded Courtyard

As this land enters, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type or activate an ability of a creature source of the chosen type.

Fires of Yavimaya

Creatures you control have haste.
Sacrifice this enchantment: Target creature gets +2/+2 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."

For the Ancestors

Choose a creature type. Look at the top six cards of your library. You may reveal any number of cards of the chosen type from among them and put the revealed cards into your hand. Put the rest on the bottom of your library in a random order.
Flashback {3}{G} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

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.

Atarka, World Render

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

Teneb, the Harvester

Flying
Whenever Teneb deals combat damage to a player, you may pay {2}{B}. If you do, put target creature card from a graveyard onto the battlefield under your control.

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."

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.

Ojutai, Soul of Winter

Flying, vigilance
Whenever a Dragon you control attacks, tap target nonland permanent an opponent controls. That permanent doesn't untap during its controller's next untap step.

Crucible of the Spirit Dragon

{T}: Add {C}.
{1}, {T}: Put a storage counter on this land.
{T}, Remove X storage counters from this land: Add X mana in any combination of colors. Spend this mana only to cast Dragon spells or activate abilities of Dragons.

Rakdos Carnarium

This land enters tapped.
When this land enters, return a land you control to its owner's hand.
{T}: Add {B}{R}.

Dragonlord's Servant

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

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.

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.

Bonehoard Dracosaur

Flying, first strike
At the beginning of your upkeep, exile the top two cards of your library. You may play them this turn. If you exiled a land card this way, create a 3/1 red Dinosaur creature token. If you exiled a nonland card this way, create a Treasure token.

Sarkhan's Unsealing

Whenever you cast a creature spell with power 4, 5, or 6, this enchantment deals 4 damage to any target.
Whenever you cast a creature spell with power 7 or greater, this enchantment deals 4 damage to each opponent and each creature and planeswalker they control.

Kindred Discovery

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

Command Tower

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

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.

Thrakkus the Butcher

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

Fellwar Stone

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

Swamp

Last March of the Ents

This spell can't be countered.
Draw cards equal to the greatest toughness among creatures you control, then put any number of creature cards from your hand onto the battlefield.

Up the Beanstalk

When this enchantment enters and whenever you cast a spell with mana value 5 or greater, draw a card.

Commander's Sphere

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

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.

Kolaghan, the Storm's Fury

Flying
Whenever a Dragon you control attacks, creatures you control get +1/+0 until end of turn.
Dash {3}{B}{R} (You may cast this spell for its dash cost. If you do, it gains haste, and it's returned from the battlefield to its owner's hand at the beginning of the next end step.)

Steel Hellkite

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

Morophon, the Boundless

Changeling (This card is every creature type.)
As Morophon enters, choose a creature type.
Spells of the chosen type you cast cost {W}{U}{B}{R}{G} less to cast. This effect reduces only the amount of colored mana you pay.
Other creatures you control of the chosen type get +1/+1.

Mountain

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.

Izzet Boilerworks

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

Urza's Incubator

As this artifact enters, choose a creature type.
Creature spells of the chosen type cost {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.)

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.

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.

Beledros Witherbloom

Flying
At the beginning of each upkeep, create a 1/1 black and green Pest creature token with "When this token dies, you gain 1 life."
Pay 10 life: Untap all lands you control. Activate only once each turn.

Dragonhawk, Fate's Tempest

Flying
Whenever Dragonhawk enters or attacks, exile the top X cards of your library, where X is the number of creatures you control with power 4 or greater. You may play those cards until your next end step. At the beginning of your next end step, Dragonhawk deals 2 damage to each opponent for each of those cards that are still exiled.

Patriarch's Bidding

Each player chooses a creature type. Each player returns all creature cards of a type chosen this way from their graveyard to the battlefield.

The Ur-Dragon

Eminence — As long as The Ur-Dragon is in the command zone or on the battlefield, other Dragon spells you cast cost {1} less to cast.
Flying
Whenever one or more Dragons you control attack, draw that many cards, then you may put a permanent card from your hand onto the battlefield.

Defiant Thundermaw

Flying, trample
Whenever a Dragon you control attacks, it deals 2 damage to any target.

Invasion of Tarkir

(As a Siege enters, choose an opponent to protect it. You and others can attack it. When it's defeated, exile it, then cast it transformed.)
When this Siege enters, reveal any number of Dragon cards from your hand. When you do, this Siege deals X plus 2 damage to any other target, where X is the number of cards revealed this way. (X can be 0.)

Invasion of Tarkir // Defiant Thundermaw

Evolving Wilds

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

Ancient Gold Dragon

Flying
Whenever this creature deals combat damage to a player, roll a d20. You create a number of 1/1 blue Faerie Dragon creature tokens with flying equal to the result.

Monastery Siege

As this enchantment enters, choose Khans or Dragons.
• Khans — At the beginning of your draw step, draw an additional card, then discard a card.
• Dragons — Spells your opponents cast that target you or a permanent you control cost {2} more to cast.

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.)

Ancient Brass Dragon

Flying
Whenever this creature deals combat damage to a player, roll a d20. When you do, put any number of target creature cards with total mana value X or less from graveyards onto the battlefield under your control, where X is the result.

Terror of the Peaks

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

Terramorphic Expanse

Dragonspeaker Shaman

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

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.

Tamiyo's Safekeeping

Target permanent you control gains hexproof and indestructible until end of turn. You gain 2 life. (A permanent 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.)

Boros Garrison

This land enters tapped.
When this land enters, return a land you control to its owner's hand.
{T}: Add {R}{W}.

Hellkite Charger

Flying, haste
Whenever this creature attacks, you may pay {5}{R}{R}. If you do, untap all attacking creatures and after this phase, there is an additional combat phase.

Crux of Fate

Choose one —
• Destroy all Dragon creatures.
• Destroy all non-Dragon creatures.

Exotic Orchard

Silumgar, the Drifting Death

Flying, hexproof
Whenever a Dragon you control attacks, creatures defending player controls get -1/-1 until end of turn.

Arcane Signet

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.

Island

Rith, Liberated Primeval

Flying, ward {2}
Other Dragons you control have ward {2}.
At the beginning of your end step, if a creature or planeswalker an opponent controlled was dealt excess damage this turn, create a 4/4 red Dragon creature token with flying.

Birds of Paradise

Smuggler's Surprise

Spree (Choose one or more additional costs.)
+ {2} — Mill four cards. You may put up to two creature and/or land cards from among the milled cards into your hand.
+ {4}{G} — You may put up to two creature cards from your hand onto the battlefield.
+ {1} — Creatures you control with power 4 or greater gain hexproof and indestructible until end of turn.

Wooded Foothills

{T}, Pay 1 life, Sacrifice this land: Search your library for a Mountain or Forest card, put it onto the battlefield, then shuffle.

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control. It can attack and {T} no matter when it came under your control.)
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)