Is Geth, Lord of the Vault legal in Standard, Modern, and Commander?

Geth, Lord of the Vault is legal in: Modern, Legacy, Vintage, Commander.

What type of card is Geth, Lord of the Vault?

Geth, Lord of the Vault is a Legendary Creature — Phyrexian Zombie. Its oracle text reads: "Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.) {X}{B}: Put target artifact or creature card with mana value X from an opponent's graveyard onto the battlefield under your control tapped. Then that player mills X cards."

Geth, Lord of the Vault

Legendary Creature — Phyrexian Zombie

Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)

: Put target artifact or creature card with mana value X from an opponent's graveyard onto the battlefield under your control tapped. Then that player mills X cards.