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.

Shivan Dragon

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

Dragon Fodder

Create two 1/1 red Goblin creature tokens.

Abrade

Choose one —
• Abrade deals 3 damage to target creature.
• Destroy target artifact.

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."

Predator Dragon

Flying, haste
Devour 2 (As this enters, you may sacrifice any number of creatures. This creature enters with twice that many +1/+1 counters on it.)

Spit Flame

Spit Flame deals 4 damage to target creature.
Whenever a Dragon you control enters, you may pay {R}. If you do, return Spit Flame from your graveyard to your hand.

Mountain

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.

Crucible of Fire

Drakuseth, Maw of Flames

Flying
Whenever Drakuseth attacks, it deals 4 damage to any target and 3 damage to each of up to two other targets.

Seething Song

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's Servant

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

Dragonspeaker Shaman

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

Siege Dragon

Flying
When Siege Dragon enters, destroy all Walls your opponents control.
Whenever Siege Dragon attacks, if defending player controls no Walls, it deals 2 damage to each creature without flying that player controls.

Two-Headed Dragon

Flying
Menace (This creature can't be blocked except by two or more creatures.)
Two-Headed Dragon can block an additional creature each combat.
{1}{R}: Two-Headed Dragon gets +2/+0 until end of turn.

Flameblast Dragon

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

Ancient Hellkite

Flying
{R}: Ancient Hellkite deals 1 damage to target creature defending player controls. Activate only if Ancient Hellkite is attacking.