Is Possessed Goat legal in Standard, Modern, and Commander?

Possessed Goat is legal in: Standard, Modern, Pioneer, Legacy, Vintage, Commander, Pauper, Historic.

Possessed Goat

Q: What type of card is Possessed Goat?

Possessed Goat is a Creature — Goat. Its oracle text reads: "{3}, Discard a card: Put three +1/+1 counters on this creature and it becomes a black Demon in addition to its other colors and types. Activate only once."

Creature — Goat

, Discard a card: Put three +1/+1 counters on this creature and it becomes a black Demon in addition to its other colors and types. Activate only once.