Dracogenesis

You may cast Dragon spells without paying their mana costs.

Tiamat

Flying
When Tiamat enters, if you cast it, search your library for up to five Dragon cards not named Tiamat that each have different names, reveal them, put them into your hand, then shuffle.

Omniscience

You may cast spells from your hand without paying their mana costs.

Command Beacon

{T}: Add {C}.
{T}, Sacrifice this land: Put your commander into your hand from the command zone.

Stormscale Scion

Flying
Other Dragons you control get +1/+1.
Storm (When you cast this spell, copy it for each spell cast before it this turn. Copies become tokens.)

Hellkite Courser

Flying
When this creature enters, you may put a commander you own from the command zone onto the battlefield. It gains haste. Return it to the command zone at the beginning of the next end step.

Sneak Attack

{R}: You may put a creature card from your hand onto the battlefield. That creature gains haste. Sacrifice the creature at the beginning of the next end step.

Show and Tell

Each player may put an artifact, creature, enchantment, or land card from their hand onto the battlefield.