Is Harbinger of the Hunt legal in Standard, Modern, and Commander?

Harbinger of the Hunt is legal in: Modern, Pioneer, Legacy, Vintage, Commander.

What type of card is Harbinger of the Hunt?

Harbinger of the Hunt is a Creature — Dragon. Its oracle text reads: "Flying {2}{R}: This creature deals 1 damage to each creature without flying. {2}{G}: This creature deals 1 damage to each other creature with flying. *An Atarka dragon's exhale cooks what its inhale consumes.* Power/Toughness: 5/3"