Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)

Vigilance, lifelink

Whenever a nontoken creature enters the battlefield under your control, populate. (Create a token that's a copy of a creature token you control.)

Whenever a creature enters the battlefield under your control, you may pay {1}. If you do, draw a card.