Is Cateran Enforcer legal in Standard, Modern, and Commander?

Cateran Enforcer is legal in: Legacy, Vintage, Commander.

What type of card is Cateran Enforcer?

Cateran Enforcer is a Creature — Horror Mercenary. Its oracle text reads: "Fear (This creature can't be blocked except by artifact creatures and/or black creatures.) {4}, {T}: Search your library for a Mercenary permanent card with mana value 4 or less, put it onto the battlefield, then shuffle."