Is Foot Ninjas legal in Standard, Modern, and Commander?

Foot Ninjas is legal in: Standard, Modern, Pioneer, Legacy, Vintage, Commander, Pauper, Historic.

Foot Ninjas

Q: What type of card is Foot Ninjas?

Foot Ninjas is a Creature — Human Ninja. Its oracle text reads: "Sneak {3}{W/B} (You may cast this spell for {3}{W/B} if you also return an unblocked attacker you control to hand during the declare blockers step. It enters tapped and attacking.) When this creature enters, you gain 3 life."

Creature — Human Ninja

Sneak (You may cast this spell for if you also return an unblocked attacker you control to hand during the declare blockers step. It enters tapped and attacking.)