Terror of the Peaks

Flying
Spells your opponents cast that target Terror of the Peaks cost an additional 3 life to cast.
Whenever another creature you control enters, Terror of the Peaks deals damage equal to that creature's power to any target.

Curse of the Pierced Heart

Enchant player
At the beginning of enchanted player's upkeep, Curse of the Pierced Heart deals 1 damage to that player or a planeswalker that player controls.

Dragonspeaker Shaman

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

Meteor Golem

When this creature enters, destroy target nonland permanent an opponent controls.

Mountain

Nesting Dragon

Flying
Landfall — Whenever a land you control enters, create a 0/2 red Dragon Egg creature token with defender and "When this creature dies, create a 2/2 red Dragon creature token with flying and '{R}: This creature 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.

Backdraft Hellkite

Flying
Whenever Backdraft Hellkite attacks, each instant and sorcery card in your graveyard gains flashback until end of turn. The flashback cost is equal to its mana cost.

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.

Minion of the Mighty

Menace
Pack tactics — Whenever Minion of the Mighty attacks, if you attacked with creatures with total power 6 or greater this combat, you may put a Dragon creature card from your hand onto the battlefield tapped and attacking.

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's Claw

Whenever a player casts a red spell, you may gain 1 life.

Ryusei, the Falling Star

Flying
When Ryusei, the Falling Star dies, it deals 5 damage to each creature without flying.

Crucible of Fire

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."

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.

Obsidian Charmaw

This spell costs {1} less to cast for each land your opponents control that could produce {C}.
Flying
When Obsidian Charmaw enters, destroy target nonbasic land an opponent controls.

Chalice of Death

Chalice of Life

{T}: You gain 1 life. Then if you have at least 10 life more than your starting life total, transform Chalice of Life.

Chalice of Life // Chalice of Death

Armillary Sphere

{2}, {T}, Sacrifice Armillary Sphere: Search your library for up to two basic land cards, reveal them, put them into your hand, then shuffle.

Red Dragon

Flying
Fire Breath — When Red Dragon enters, it deals 4 damage to each opponent.

Elixir of Immortality

{2}, {T}: You gain 5 life. Shuffle Elixir of Immortality and your graveyard into their owner's library.

Dragonkin Berserker

First strike
Boast abilities you activate cost {1} less to activate for each Dragon you control.
Boast — {4}{R}: Create a 5/5 red Dragon creature token with flying. (Activate only if this creature attacked this turn and only once each turn.)

Dragon Whelp

Flying
{R}: Dragon Whelp gets +1/+0 until end of turn. If this ability has been activated four or more times this turn, sacrifice Dragon Whelp at the beginning of the next end step.

Roast

Roast deals 5 damage to target creature without flying.

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.