Is Hythonia the Cruel legal in Standard, Modern, and Commander?

Hythonia the Cruel is legal in: Modern, Pioneer, Legacy, Vintage, Commander.

Hythonia the Cruel

Q: What type of card is Hythonia the Cruel?

Hythonia the Cruel is a Legendary Creature — Gorgon. Its oracle text reads: "Deathtouch {6}{B}{B}: Monstrosity 3. (If this creature isn't monstrous, put three +1/+1 counters on it and it becomes monstrous.) When Hythonia becomes monstrous, destroy all non-Gorgon creatures. Power/Toughness: 4/6"