Sarkhan's Triumph

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

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.

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.

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.

Dragonborn Champion

Trample
Whenever a source you control deals 5 or more damage to a player, draw a card.

Primevals' Glorious Rebirth

(You may cast a legendary sorcery only if you control a legendary creature or planeswalker.)
Return all legendary permanent cards from your graveyard to the battlefield.

Amareth, the Lustrous

Flying
Whenever another permanent you control enters, look at the top card of your library. If it shares a card type with that permanent, you may reveal that card and put it into your hand.

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.

Despark

Exile target permanent with mana value 4 or greater.

Belbe's Portal

As Belbe's Portal enters, choose a creature type.
{3}, {T}: You may put a creature card of the chosen type from your hand onto the battlefield.

Dromoka, the Eternal

Flying
Whenever a Dragon you control attacks, bolster 2. (Choose a creature with the least toughness among creatures you control and put two +1/+1 counters on it.)

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.)

Bladewing the Risen

Flying
When Bladewing the Risen 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.

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.

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.

Silumgar, the Drifting Death

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

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.)

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.

Intet, the Dreamer

Flying
Whenever Intet, the Dreamer deals combat damage to a player, you may pay {2}{U}. If you do, exile the top card of your library face down. You may look at that card for as long as it remains exiled. You may play that card without paying its mana cost for as long as Intet remains on the battlefield.

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.

Zoological Study

Mill five cards, then return a creature card milled this way to your hand. (Then exile this card. You may cast the artifact later from exile.)

Monster Manual

{1}{G}, {T}: You may put a creature card from your hand onto the battlefield.

Monster Manual // Zoological Study

Thrakkus the Butcher

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