Furnace Whelp

Flying
{R}: Furnace Whelp gets +1/+0 until end of turn.

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.

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.

Rapacious Dragon

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

Dragon Fodder

Create two 1/1 red Goblin creature tokens.

Mountain

Draconic Roar

As an additional cost to cast this spell, you may reveal a Dragon card from your hand.
Draconic Roar deals 3 damage to target creature. If you revealed a Dragon card or controlled a Dragon as you cast this spell, Draconic Roar deals 3 damage to that creature's controller.

Dragonlord's Servant

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

Hellkite Punisher

Flying
{R}: Hellkite Punisher gets +1/+0 until end of turn.

Sarkhan's Rage

Sarkhan's Rage deals 5 damage to any target. If you control no Dragons, Sarkhan's Rage deals 2 damage to you.

Lightning Shrieker

Flying, trample, haste
At the beginning of the end step, Lightning Shrieker's owner shuffles it into their library.

Dragon Hatchling

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

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.")