Carnelian Orb of Dragonkind

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

Niv-Mizzet, the Firemind

Flying
Whenever you draw a card, Niv-Mizzet deals 1 damage to any target.
{T}: Draw a card.

Jaded Sell-Sword

When this creature enters, if mana from a Treasure was spent to cast it, it gains first strike and haste until end of turn.

Capsizing Wave

Return target creature to its owner's hand. (Then exile this card. You may cast the creature later from exile.)

Sword Coast Serpent

This creature can't be blocked as long as you've cast a noncreature spell this turn.

Sword Coast Serpent // Capsizing Wave

Patron of the Arts

When this creature enters or dies, create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Hypersonic Dragon

Flying, haste
You may cast sorcery spells as though they had flash. (You may cast them any time you could cast an instant.)

Dragon Cultist

Commander creatures you own have "At the beginning of your end step, if a source you controlled dealt 5 or more damage this turn, create a 4/4 red Dragon creature token with flying."

Tiamat's Fanatics

Haste
Myriad (Whenever this creature 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.)

Lozhan, Dragons' Legacy

Flying
Whenever you cast an Adventure or Dragon spell, Lozhan deals damage equal to that spell's mana value to any target that isn't a commander.

Shockmaw Dragon

Flying
Whenever this creature deals combat damage to a player, it deals 1 damage to each creature that player controls.

Archive Dragon

Flying
Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
When this creature enters, scry 2.

Draconic Lore

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

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.

Bhaal's Invoker

Scorching Ray — {8}: This creature deals 4 damage to each opponent.

Sarkhan, the Dragonspeaker

+1: Until end of turn, Sarkhan 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 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."

Vengeful Ancestor

Flying
Whenever this creature enters or attacks, goad target creature. (Until your next turn, that creature attacks each combat if able and attacks a player other than you if able.)
Whenever a goaded creature attacks, it deals 1 damage to its controller.

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.

Furnace Whelp

Flying
{R}: This creature gets +1/+0 until end of turn.

Spinerock Knoll

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.)
This land enters tapped.
{T}: Add {R}.
{R}, {T}: You may play the exiled card without paying its mana cost if an opponent was dealt 7 or more damage this turn.

Pseudodragon Familiar

Flying
{2}{U}: Target creature gains flying until end of turn.

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.)

Dragonborn Looter

{1}, {T}: Draw a card, then discard a card.

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.

Shimmer Dragon

Flying
As long as you control four or more artifacts, this creature has hexproof. (It can't be the target of spells or abilities your opponents control.)
Tap two untapped artifacts you control: Draw a card.

Tyrant of Kher Ridges

Flying
When this creature enters, it deals 4 damage to any target.
{R}: This creature gets +1/+0 until end of turn.

Kolaghan Warmonger

Haste
Whenever this creature attacks, look at the top six 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.

Scourge of the Throne

Flying
Dethrone (Whenever this creature attacks the player with the most life or tied for most life, put a +1/+1 counter on it.)
Whenever this creature attacks for the first time each turn, if it's attacking the player with the most life or tied for most life, untap all attacking creatures. After this phase, there is an additional combat phase.

Nimbleclaw Adept

Bigby's Hand — {T}: Untap two other target permanents. Activate only as a sorcery and only once each turn.

Demanding Dragon

Flying
When this creature enters, it deals 5 damage to target opponent unless that player sacrifices a creature of their choice.

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

Red Dragon

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

The Elder Dragon War

Read ahead (Choose a chapter and start with that many lore counters. Add one after your draw step. Skipped chapters don't trigger. Sacrifice after III.)
I — This Saga deals 2 damage to each creature and each opponent.
II — Discard any number of cards, then draw that many cards.
III — Create a 4/4 red Dragon creature token with flying.

Loch Dragon

Flying
Whenever this creature enters or attacks, you may discard a card. If you do, 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.)

Dragon Whelp

Flying
{R}: This creature gets +1/+0 until end of turn. If this ability has been activated four or more times this turn, sacrifice this creature at the beginning of the next end step.

Swashbuckler Extraordinaire

When this creature enters, create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")
Whenever you attack, you may sacrifice one or more Treasures. When you do, up to that many target creatures gain double strike until end of turn.

Feywild Visitor

Commander creatures you own have "Whenever one or more nontoken creatures you control deal combat damage to a player, you create a 1/1 blue Faerie Dragon creature token with flying."

Shivan Branch-Burner

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Flying, haste

Oceanus Dragon

Flying
When this creature enters, tap target creature an opponent controls. Goad it. (Until your next turn, that creature attacks each combat if able and attacks a player other than you if able.)

Skyship Stalker

Flying
{R}: This creature gets +1/+0 until end of turn.
{R}: This creature gains first strike until end of turn.
{R}: This creature gains haste until end of turn.

Goddric, Cloaked Reveler

Haste
Celebration — As long as two or more nonland permanents entered the battlefield under your control this turn, Goddric is a Dragon with base power and toughness 4/4, flying, and "{R}: Dragons you control get +1/+0 until end of turn." (It loses all other creature types.)

Furnace Hellkite

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
Flying
{R}: This creature gets +1/+0 until end of turn.

Rapacious Dragon

Flying
When this creature enters, create two Treasure tokens. (They're artifacts with "{T}, Sacrifice this token: Add one mana of any color.")

Hellkite Whelp

Flying
Whenever this creature attacks, it deals 1 damage to target creature defending player controls.

Sarkhan the Masterless

Whenever a creature attacks you or a planeswalker you control, each Dragon you control deals 1 damage to that creature.
+1: Until end of turn, each planeswalker you control becomes a 4/4 red Dragon creature and gains flying.
−3: Create a 4/4 red Dragon creature token with flying.

Juvenile Mist Dragon

Flying
Confounding Clouds — When this creature enters, for each opponent, tap up to one target creature that player controls. Each of those creatures doesn't untap during its controller's next untap step.