Is Grave Defiler legal in Standard, Modern, and Commander?

Grave Defiler is legal in: Legacy, Vintage, Commander.

Grave Defiler

Q: What type of card is Grave Defiler?

Grave Defiler is a Creature — Zombie. Its oracle text reads: "When this creature enters, reveal the top four cards of your library. Put all Zombie cards revealed this way into your hand and the rest on the bottom of your library in any order. {1}{B}: Regenerate this creature. Power/Toughness: 2/1"

Creature — Zombie

When this creature enters, reveal the top four cards of your library. Put all Zombie cards revealed this way into your hand and the rest on the bottom of your library in any order.

: Regenerate this creature.