Mardu Scout

Dash {1}{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.)

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.

Teetering Peaks

Teetering Peaks enters tapped.
When Teetering Peaks enters, target creature gets +2/+0 until end of turn.
{T}: Add {R}.

Dragon Roost

{5}{R}{R}: Create a 5/5 red Dragon creature token with flying. (It can't be blocked except by creatures with flying or reach.)

Verix Bladewing

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

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.

Dragon Hatchling

Flying
{R}: Dragon Hatchling gets +1/+0 until end of turn.

Thriving Bluff

Thriving Bluff enters tapped. As it enters, choose a color other than red.
{T}: Add {R} or one mana of the chosen color.

Irencrag Feat

Add seven {R}. You can cast only one more spell this turn.

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.

Cathartic Reunion

As an additional cost to cast this spell, discard two cards.
Draw three cards.

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.

Dragon Mage

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

Alena, Kessig Trapper

First strike
{T}: Add an amount of {R} equal to the greatest power among creatures you control that entered this turn.
Partner (You can have two commanders if both have partner.)

Archwing Dragon

Flying, haste
At the beginning of the end step, return Archwing Dragon to its owner's hand.

Gadrak, the Crown-Scourge

Flying
Gadrak, the Crown-Scourge can't attack unless you control four or more artifacts.
At the beginning of your end step, create a Treasure token for each nontoken creature that died this turn. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

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.

Mountain

Crucible of Fire

Viashino Sandsprinter

Trample, haste
At the beginning of the end step, return Viashino Sandsprinter to its owner's hand. (Return it only if it's on the battlefield.)
Cycling {R} ({R}, Discard this card: Draw a card.)

Dragonlord's Servant

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

Comet Storm

Multikicker {1} (You may pay an additional {1} any number of times as you cast this spell.)
Choose any target, then choose another target for each time this spell was kicked. Comet Storm deals X damage to each of them.

Consulate Dreadnought

Crew 6 (Tap any number of creatures you control with total power 6 or more: This Vehicle becomes an artifact creature until end of turn.)

Descent of the Dragons

Destroy any number of target creatures. For each creature destroyed this way, its controller creates a 4/4 red Dragon creature token with flying.

Flameblast Dragon

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

Faithless Looting

Draw two cards, then discard two cards.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Mana-Charged Dragon

Flying, trample
Join forces — Whenever Mana-Charged Dragon attacks or blocks, each player starting with you may pay any amount of mana. Mana-Charged Dragon gets +X/+0 until end of turn, where X is the total amount of mana paid this way.

Bogardan Dragonheart

Sacrifice another creature: Until end of turn, Bogardan Dragonheart becomes a Dragon with base power and toughness 4/4, flying, and haste.

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."

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.")

Dragonspeaker Shaman

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

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.

Dragon Egg

Defender
When Dragon Egg dies, create a 2/2 red Dragon creature token with flying and "{R}: This creature gets +1/+0 until end of turn."

Hellkite Charger

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

Inferno Hellion

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
At the beginning of each end step, if Inferno Hellion attacked or blocked this turn, its owner shuffles it into their library.

Moltensteel Dragon

({R/P} can be paid with either {R} or 2 life.)
Flying
{R/P}: Moltensteel Dragon gets +1/+0 until end of turn.