Is Fleshtaker legal in Standard, Modern, and Commander?

Fleshtaker is legal in: Modern, Pioneer, Legacy, Vintage, Commander, Historic.

Fleshtaker

Q: What type of card is Fleshtaker?

Fleshtaker is a Creature — Human Assassin. Its oracle text reads: "Whenever you sacrifice another creature, you gain 1 life and scry 1. (Look at the top card of your library. You may put that card on the bottom.) {1}, Sacrifice another creature: This creature gets +2/+2 until end of turn. *A soulless husk of endless hunger.* Power/Toughness: 2/2"