Is Dirge Bat legal in Standard, Modern, and Commander?

Dirge Bat is legal in: Modern, Pioneer, Legacy, Vintage, Commander, Historic.

Dirge Bat

Q: What type of card is Dirge Bat?

Dirge Bat is a Creature — Bat. Its oracle text reads: "Mutate {4}{B}{B} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.) Flash Flying Whenever this creature mutates, destroy target creature or planeswalker an opponent controls. Power/Toughness: 3/3"

Creature — Bat

Mutate (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)