Is Primordial Hydra legal in Standard, Modern, and Commander?

Primordial Hydra is legal in: Modern, Legacy, Vintage, Commander.

Primordial Hydra

Q: What type of card is Primordial Hydra?

Primordial Hydra is a Creature — Hydra. Its oracle text reads: "This creature enters with X +1/+1 counters on it. At the beginning of your upkeep, double the number of +1/+1 counters on this creature. This creature has trample as long as it has ten or more +1/+1 counters on it. Power/Toughness: 0/0"