Draconic Ritual 3R
Instant
Add RRRRRR to your mana pool. Until end of turn, creatures you control gain "R: This creature gets +1/+0 until end of turn".
Dragon's Hoard 3
Artifact
3, Sacrifice ~: Search your library for a card and put it into your hand. Then shuffle your library.
Draconify 2RR
Enchantment - Aura
Enchant creature
Enchanted creature is 6/6, has flying and trample, and is a red Dragon in addition to its other colours and types.
Young Dragonlet 1RR
Creature - Dragon
Flying
~ is indestructible as long as you control another Dragon.
2/2
Yaron, Drakhon Warrior 3RR
Planeswalker - Yaron
Whenever a source deals damage to ~, ~ deals that much damage to that source's controller.
+2: Until end of turn, up to one target creature gains "R: This creature gets +1/+0 until end of turn".
-10: Search your library for any number of Dragon creature cards and put them into play, then shuffle your library.
{6}
Valley of the Mythics
Land
~ comes into play tapped.
T, Pay 1 life: Add one mana of any colour to your mana pool. Put a charge counter on ~.
4, T, Remove three charge counters from ~: Put a 5/5 red Dragon creature token with flying into play.