Fledgling Dragon

Flying
Threshold — As long as seven or more cards are in your graveyard, Fledgling Dragon gets +3/+3 and has "{R}: Fledgling Dragon gets +1/+0 until end of turn."

Cavern Crawler

Mountainwalk (This creature can't be blocked as long as defending player controls a Mountain.)
{R}: Cavern Crawler gets +1/-1 until end of turn.

Bayou Dragonfly

Flying; swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)

Dragon Tyrant

Flying, trample
Double strike (This creature deals both first-strike and regular combat damage.)
At the beginning of your upkeep, sacrifice Dragon Tyrant unless you pay {R}{R}{R}{R}.
{R}: Dragon Tyrant gets +1/+0 until end of turn.

Boris Devilboon

{2}{B}{R}, {T}: Create a 1/1 black and red Demon creature token named Minor Demon.

Darigaaz, the Igniter

Flying
Whenever Darigaaz, the Igniter deals combat damage to a player, you may pay {2}{R}. If you do, choose a color, then that player reveals their hand and Darigaaz deals damage to the player equal to the number of cards of that color revealed this way.

Fire Dragon

Flying
When Fire Dragon enters, it deals damage to target creature equal to the number of Mountains you control.

Canopy Dragon

Trample
{1}{G}: Canopy Dragon gains flying and loses trample until end of turn.

Catacomb Dragon

Flying
Whenever Catacomb Dragon becomes blocked by a nonartifact, non-Dragon creature, that creature gets -X/-0 until end of turn, where X is half the creature's power, rounded down.

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.

Fumarole

As an additional cost to cast this spell, pay 3 life.
Destroy target creature and target land.

Urza's Incubator

As Urza's Incubator enters, choose a creature type.
Creature spells of the chosen type cost {2} less to cast.

Covetous Dragon

Flying
When you control no artifacts, sacrifice Covetous Dragon.

Zirilan of the Claw

{1}{R}{R}, {T}: Search your library for a Dragon permanent card, put that card onto the battlefield, then shuffle. That Dragon gains haste until end of turn. Exile it at the beginning of the next end step.

Brimstone Dragon

All Hallow's Eve

Exile All Hallow's Eve with two scream counters on it.
At the beginning of your upkeep, if All Hallow's Eve is exiled with a scream counter on it, remove a scream counter from it. If there are no more scream counters on it, put it into your graveyard and each player returns all creature cards from their graveyard to the battlefield.

Dragon Fangs

Enchant creature
Enchanted creature gets +1/+1 and has trample.
When a creature with mana value 6 or greater enters, you may return Dragon Fangs from your graveyard to the battlefield attached to that creature.

Hunting Cheetah

Whenever Hunting Cheetah deals damage to an opponent, you may search your library for a Forest card, reveal that card, put it into your hand, then shuffle.

Dragonspeaker Shaman

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

Sarkhan the Mad

0: Reveal the top card of your library and put it into your hand. Sarkhan the Mad deals damage to himself equal to that card's mana value.
−2: Target creature's controller sacrifices it, then that player creates a 5/5 red Dragon creature token with flying.
−4: Each Dragon creature you control deals damage equal to its power to target player or planeswalker.

Tuknir Deathlock

Flying
{R}{G}, {T}: Target creature gets +2/+2 until end of turn.

Ebon Dragon

Flying
When Ebon Dragon enters, you may have target opponent discard a card.

Dragon Shadow

Enchant creature
Enchanted creature gets +1/+0 and has fear. (It can't be blocked except by artifact creatures and/or black creatures.)
When a creature with mana value 6 or greater enters, you may return Dragon Shadow from your graveyard to the battlefield attached to that creature.