Is Narfi, Betrayer King legal in Standard, Modern, and Commander?

Narfi, Betrayer King is legal in: Modern, Pioneer, Legacy, Vintage, Commander.

What type of card is Narfi, Betrayer King?

Narfi, Betrayer King is a Legendary Snow Creature — Zombie Wizard. Its oracle text reads: "Other snow and Zombie creatures you control get +1/+1. {S}{S}{S}: Return this card from your graveyard to the battlefield tapped. ({S} can be paid with one mana from a snow source.) *To serve the god of death, Narfi forfeited the warmth of life.* Power/Toughness: 4/3"