Is Sentry Oak legal in Standard, Modern, and Commander?

Sentry Oak is legal in: Modern, Legacy, Vintage, Commander.

Sentry Oak

Q: What type of card is Sentry Oak?

Sentry Oak is a Creature — Treefolk Warrior. Its oracle text reads: "Defender At the beginning of combat on your turn, you may clash with an opponent. If you win, this creature gets +2/+0 and loses defender until end of turn. (Each clashing player reveals the top card of their library, then puts that card on their choice of the top or bottom. A player wins if their card had a greater mana value.) Power/Toughness: 3/5"

Creature — Treefolk Warrior

Defender

At the beginning of combat on your turn, you may clash with an opponent. If you win, this creature gets +2/+0 and loses defender until end of turn. (Each clashing player reveals the top card of their library, then puts that card on their choice of the top or bottom. A player wins if their card had a greater mana value.)

Power/Toughness: 3/5

Set Lorwyn

Rarity Uncommon

Mana Value 5

Artist Warren Mahy

Collector # 38

Scryfall