Polukranos, World Eater

Vigilance Whenever this creature enters or attacks, you may return target permanent card with mana value 3 or less from your graveyard to the battlefield.

Whenever this creature becomes blocked by a creature, this creature deals 1 damage to that creature.

R/W: This creature becomes a Kithkin Spirit with base power and toughness 2/2. R/WR/WR/W: If this creature is a Spirit, it becomes a Kithkin Spirit Warrior with base power and toughness 4/4. R/WR/WR/WR/WR/WR/W: If this creature is a Warrior, it becomes a Kithkin Spirit Warrior Avatar with base power and toughness 8/8, flying, and first strike.

Flying Whenever this creature attacks, each attacking Human gains flying until end of turn.

Double strike (This creature deals both first-strike and regular combat damage.)

Vigilance

1, T: This creature deals 1 damage to target creature. Tap that creature.

Vigilance RW: This creature gets +2/+0 until end of turn. RW: This creature gains first strike until end of turn.