Is Fleshwrither legal in Standard, Modern, and Commander?

Fleshwrither is legal in: Modern, Legacy, Vintage, Commander.

Fleshwrither

Q: What type of card is Fleshwrither?

Fleshwrither is a Creature — Horror. Its oracle text reads: "Transfigure {1}{B}{B} ({1}{B}{B}, Sacrifice this creature: Search your library for a creature card with the same mana value as this creature, put that card onto the battlefield, then shuffle. Transfigure only as a sorcery.) Power/Toughness: 3/3"

Creature — Horror

Transfigure (, Sacrifice this creature: Search your library for a creature card with the same mana value as this creature, put that card onto the battlefield, then shuffle. Transfigure only as a sorcery.)