Is Thriving Grubs legal in Standard, Modern, and Commander?

Thriving Grubs is legal in: Modern, Pioneer, Legacy, Vintage, Commander, Pauper.

Thriving Grubs

Q: What type of card is Thriving Grubs?

Thriving Grubs is a Creature — Gremlin. Its oracle text reads: "When this creature enters, you get {E}{E} (two energy counters). Whenever this creature attacks, you may pay {E}{E}. If you do, put a +1/+1 counter on it. *Some passengers ride without tickets.* Power/Toughness: 2/1"