Is Foster legal in Standard, Modern, and Commander?

Foster is legal in: Legacy, Vintage, Commander.

What type of card is Foster?

Foster is an Enchantment. Its oracle text reads: "Whenever a creature you control dies, you may pay {1}. If you do, reveal cards from the top of your library until you reveal a creature card. Put that card into your hand and the rest into your graveyard."

Foster

Enchantment

Whenever a creature you control dies, you may pay . If you do, reveal cards from the top of your library until you reveal a creature card. Put that card into your hand and the rest into your graveyard.