Is Boros Mastiff legal in Standard, Modern, and Commander?

Boros Mastiff is legal in: Modern, Pioneer, Legacy, Vintage, Commander, Pauper.

Boros Mastiff

Q: What type of card is Boros Mastiff?

Boros Mastiff is a Creature — Dog. Its oracle text reads: "Battalion — Whenever this creature and at least two other creatures attack, this creature gains lifelink until end of turn. (Damage dealt by a creature with lifelink also causes its controller to gain that much life.)"

Creature — Dog

Battalion — Whenever this creature and at least two other creatures attack, this creature gains lifelink until end of turn. (Damage dealt by a creature with lifelink also causes its controller to gain that much life.)

Set Dragon's Maze

Rarity Common

Mana Value 2

Artist Kev Walker

Collector # 1

Scryfall Gatherer