Tenzivel, Lord of the Dragons

Flying, haste, trample, deathtouch
Other Dragon creatures you control get +1/+1 and have indestructible.
At the beginning of your upkeep, if you control 5 or more Dragons, put a 5/5 red Dragon creature token with flying onto the battlefield.
Whenever a Dragon you control attacks, put a 5/5 red Dragon creature token with flying onto the battlefield tapped and attacking.
"The Eldrazi don't stand a chance."