Is Unsanctioned Ancient Juggler legal in Standard, Modern, and Commander?

Unsanctioned Ancient Juggler is legal in: Commander.

Unsanctioned Ancient Juggler

Q: What type of card is Unsanctioned Ancient Juggler?

Unsanctioned Ancient Juggler is a Stickers. Its oracle text reads: "{TK}{TK} — Whenever this creature attacks, bolster 1. (Choose a creature with the least toughness among creatures you control and put a +1/+1 counter on it.) {TK}{TK}{TK}{TK} — Indestructible {TK}{TK} — 3/2 {TK}{TK}{TK} — 5/4"