Is Polukranos, World Eater legal in Standard, Modern, and Commander?

Polukranos, World Eater is legal in: Modern, Pioneer, Legacy, Vintage, Commander, Historic.

What type of card is Polukranos, World Eater?

Polukranos, World Eater is a Legendary Creature — Hydra. Its oracle text reads: "{X}{X}{G}: Monstrosity X. (If this creature isn't monstrous, put X +1/+1 counters on it and it becomes monstrous.)When Polukranos, World Eater becomes monstrous, it deals X damage divided as you choose among any number of target creatures your opponents control. Each of those creatures deals damage equal to its power to Polukranos."

Polukranos, World Eater

Legendary Creature — Hydra

: Monstrosity X. (If this creature isn't monstrous, put X +1/+1 counters on it and it becomes monstrous.)<br>When Polukranos, World Eater becomes monstrous, it deals X damage divided as you choose among any number of target creatures your opponents control. Each of those creatures deals damage equal to its power to Polukranos.