Is Squirming Mass legal in Standard, Modern, and Commander?

Squirming Mass is legal in: Legacy, Vintage, Commander, Pauper.

Squirming Mass

Q: What type of card is Squirming Mass?

Squirming Mass is a Creature — Horror. Its oracle text reads: "Fear (This creature can't be blocked except by artifact creatures and/or black creatures.) *Only the coldest hearts and the strongest stomachs can stand against it.* Power/Toughness: 1/1"