Is Gadrak, the Crown-Scourge legal in Standard, Modern, and Commander?

Gadrak, the Crown-Scourge is legal in: Modern, Pioneer, Legacy, Vintage, Commander, Historic.

Gadrak, the Crown-Scourge

Q: What type of card is Gadrak, the Crown-Scourge?

Gadrak, the Crown-Scourge is a Legendary Creature — Dragon. Its oracle text reads: "Flying Gadrak can't attack unless you control four or more artifacts. At the beginning of your end step, create a Treasure token for each nontoken creature that died this turn. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.") Power/Toughness: 5/4"

Legendary Creature — Dragon

Flying

Gadrak can't attack unless you control four or more artifacts.

At the beginning of your end step, create a Treasure token for each nontoken creature that died this turn. (It's an artifact with ", Sacrifice this token: Add one mana of any color.")