Tiamat - Dragon Queen

Flying, Deathtouch, Lifelink, Annihilator: {2}
Sacrifice {3} mana.
{t}, {w}: Roll a d20. Divide number by 2
and round down. Gain this much life.
{t}, {u}: Draw 3 cards from any library.
{t}, {b}: Put a creature from a graveyard into the battlefield.
{t}, {r}: Distribute 5 -1/-1 counters any way you like.
{t}, {x}, {g}: Summon an X/1 creature.