Is Falkenrath Marauders legal in Standard, Modern, and Commander?

Falkenrath Marauders is legal in: Modern, Legacy, Vintage, Commander, Historic.

What type of card is Falkenrath Marauders?

Falkenrath Marauders is a Creature — Vampire Warrior. Its oracle text reads: "Flying Haste (This creature can attack and {T} as soon as it comes under your control.) Whenever this creature deals combat damage to a player, put two +1/+1 counters on it."