Is Elven Bow legal in Standard, Modern, and Commander?

Elven Bow is legal in: Modern, Pioneer, Legacy, Vintage, Commander.

What type of card is Elven Bow?

Elven Bow is an Artifact — Equipment. Its oracle text reads: "When this Equipment enters, you may pay {2}. If you do, create a 1/1 green Elf Warrior creature token, then attach this Equipment to it. Equipped creature gets +1/+2 and has reach. Equip {3}"