Is Fylgja legal in Standard, Modern, and Commander?

Fylgja is legal in: Legacy, Vintage, Commander, Pauper.

What type of card is Fylgja?

Fylgja is an Enchantment — Aura. Its oracle text reads: "Enchant creatureFylgja enters with four healing counters on it.Remove a healing counter from Fylgja: Prevent the next 1 damage that would be dealt to enchanted creature this turn.{2}{W}: Put a healing counter on Fylgja."

Fylgja

Enchantment — Aura

Enchant creature<br>Fylgja enters with four healing counters on it.<br>Remove a healing counter from Fylgja: Prevent the next 1 damage that would be dealt to enchanted creature this turn.<br>: Put a healing counter on Fylgja.