Is Treeguard Duo legal in Standard, Modern, and Commander?

Treeguard Duo is legal in: Standard, Modern, Pioneer, Legacy, Vintage, Commander, Pauper, Historic.

Treeguard Duo

Q: What type of card is Treeguard Duo?

Treeguard Duo is a Creature — Frog Rabbit. Its oracle text reads: "When this creature enters, until end of turn, target creature you control gains vigilance and gets +X/+X, where X is the number of creatures you control."

Creature — Frog Rabbit

When this creature enters, until end of turn, target creature you control gains vigilance and gets +X/+X, where X is the number of creatures you control.

Set Bloomburrow

Rarity Common

Mana Value 4

Artist Mila Pesic

Collector # 200

Scryfall Gatherer