Is Skullbriar, the Walking Grave legal in Standard, Modern, and Commander?

Skullbriar, the Walking Grave is legal in: Legacy, Vintage, Commander.

Skullbriar, the Walking Grave

Q: What type of card is Skullbriar, the Walking Grave?

Skullbriar, the Walking Grave is a Legendary Creature — Zombie Elemental. Its oracle text reads: "Haste Whenever Skullbriar deals combat damage to a player, put a +1/+1 counter on it. Counters remain on Skullbriar as it moves to any zone other than a player's hand or library. Power/Toughness: 1/1"