Creatures you control get +1/+0 and have
vigilance (Attacking doesn't cause this creature to tap.) as long as you control three or more creatures.
Creatures you control also get +1/+0 and have
trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.) as long as you control six or more creatures.
Creatures you control also get +1/+0 and have
double strike (This creature deals both first-strike and regular combat damage.) as long as you control nine or more creatures.