Is Firefiend Elemental legal in Standard, Modern, and Commander?

Firefiend Elemental is legal in: Modern, Pioneer, Legacy, Vintage, Commander, Pauper.

Firefiend Elemental

Q: What type of card is Firefiend Elemental?

Firefiend Elemental is a Creature — Elemental. Its oracle text reads: "Haste (This creature can attack and {T} as soon as it comes under your control.) Renown 1 (When this creature deals combat damage to a player, if it isn't renowned, put a +1/+1 counter on it and it becomes renowned.)"