Is Oko, Thief of Crowns legal in Standard, Modern, and Commander?

Oko, Thief of Crowns is legal in: Vintage, Commander. It is banned in: Modern, Pioneer, Legacy, Historic.

Oko, Thief of Crowns

Q: What type of card is Oko, Thief of Crowns?

Oko, Thief of Crowns is a Legendary Planeswalker — Oko. Its oracle text reads: "+2: Create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this token: You gain 3 life.") +1: Target artifact or creature loses all abilities and becomes a green Elk creature with base power and toughness 3/3. −5: Exchange control of target artifact or creature you control and target creature an opponent controls with power 3 or less."