Zarath, Aspiring Lichmaster

Zombie Army tokens you control get +1/+1
Zombie Army tokens get:
• vigilance, if their power is 3 or more,
• menace, if their power is 5 or more,
• lifelink, if their power is 7 or more.
Herder of the Undead Hordes:
When a creature dies, you may pay {w/b}{w/b}{w/b}
if you do, amass 3.