Is Horned Stoneseeker legal in Standard, Modern, and Commander?

Horned Stoneseeker is legal in: Modern, Pioneer, Legacy, Vintage, Commander, Historic.

What type of card is Horned Stoneseeker?

Horned Stoneseeker is a Creature — Lizard. Its oracle text reads: "Menace When this creature enters, create a tapped Powerstone token. (It's an artifact with "{T}: Add {C}. This mana can't be spent to cast a nonartifact spell.") When this creature leaves the battlefield, sacrifice a Powerstone."