Is Enigma Thief legal in Standard, Modern, and Commander?

Enigma Thief is legal in: Legacy, Vintage, Commander.

Enigma Thief

Q: What type of card is Enigma Thief?

Enigma Thief is a Creature — Sphinx Rogue. Its oracle text reads: "Prowl {3}{U} (You may cast this spell for its prowl cost if you dealt combat damage to a player this turn with a Sphinx or Rogue.) Flying When this creature enters, for each opponent, return up to one target nonland permanent that player controls to its owner's hand."