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.

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.

Mutagenic Growth

({G/P} can be paid with either {G} or 2 life.)
Target creature gets +2/+2 until end of turn.

Mountain

Desperate Ritual

Add {R}{R}{R}.
Splice onto Arcane {1}{R} (As you cast an Arcane spell, you may reveal this card from your hand and pay its splice cost. If you do, add this card's effects to that spell.)

Generator Servant

{T}, Sacrifice Generator Servant: Add {C}{C}. If that mana is spent on a creature spell, it gains haste until end of turn. (That creature can attack and {T} as soon as it comes under your control.)

Thrill of Possibility

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

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."

O-Naginata

O-Naginata can be attached only to a creature with power 3 or greater.
Equipped creature gets +3/+0 and has trample.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Dragonlord's Servant

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

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.

Avaricious Dragon

Flying
At the beginning of your draw step, draw an additional card.
At the beginning of your end step, discard your hand.

Sarkhan's Triumph

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

Shuko

Equipped creature gets +1/+0.
Equip {0} ({0}: Attach to target creature you control. Equip only as a sorcery.)

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.

Thundermaw Hellkite

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

Slumbering Dragon

Flying
Slumbering Dragon can't attack or block unless it has five or more +1/+1 counters on it.
Whenever a creature attacks you or a planeswalker you control, put a +1/+1 counter on Slumbering Dragon.

Pyretic Ritual

Irencrag Feat

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

Inferno of the Star Mounts

This spell can't be countered.
Flying, haste
{R}: Inferno of the Star Mounts gets +1/+0 until end of turn. When its power becomes 20 this way, it deals 20 damage to any target.