Is Lobelia, Defender of Bag End legal in Standard, Modern, and Commander?

Lobelia, Defender of Bag End is legal in: Legacy, Vintage, Commander.

What type of card is Lobelia, Defender of Bag End?

Lobelia, Defender of Bag End is a Legendary Creature — Halfling Citizen. Its oracle text reads: "When Lobelia enters, look at the top card of each opponent's library and exile those cards face down. {T}, Sacrifice an artifact: Choose one — • Until end of turn, you may play a card exiled with Lobelia without paying its mana cost. • Each opponent loses 2 life and you gain 2 life. Power/Toughness: 2/2"