Red Dragon

Flying
Fire Breath — When this creature enters, it deals 4 damage to each opponent.

Demanding Dragon

Flying
When this creature enters, it deals 5 damage to target opponent unless that player sacrifices a creature of their choice.

Bogardan Hellkite

Flash
Flying
When this creature enters, it deals 5 damage divided as you choose among any number of targets.

Purphoros, Bronze-Blooded

Indestructible
As long as your devotion to red is less than five, Purphoros isn't a creature.
Other creatures you control have haste.
{2}{R}: You may put a red creature card or an artifact creature card from your hand onto the battlefield. Sacrifice it at the beginning of the next end step.

Hoarding Dragon

Flying
When this creature enters, you may search your library for an artifact card, exile it, then shuffle.
When this creature dies, you may put the exiled card into its owner's hand.

Skyline Despot

Flying
When this creature enters, you become the monarch.
At the beginning of your upkeep, if you're the monarch, create a 5/5 red Dragon creature token with flying.

Thundermaw Hellkite

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

Spawn of Thraxes

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

Lava-Field Overlord

Assist (Another player can pay up to {7} of this spell's cost.)
Flying
When this creature enters, it deals 4 damage to target creature an opponent controls.

Tyrant of Kher Ridges

Flying
When this creature enters, it deals 4 damage to any target.
{R}: This creature gets +1/+0 until end of turn.

Terror of Mount Velus

Flying
Double strike (This creature deals both first-strike and regular combat damage.)
When this creature enters, creatures you control gain double strike until end of turn.

Knollspine Dragon

Flying
When this creature enters, you may discard your hand and draw cards equal to the damage dealt to target opponent this turn.