Although the term had been used to refer to the East Coast] for several years previously (as a response to the claim that "the West Coast] is the best coast"), since 2012 "Beast Coast" has emerged as a way to refer to the new wave of fresh, young, often experimental, underground hip-hop] artists gaining prominence in New York.
Some of the most notable "Beast Coast" artists are the Pro Era collective (which includes Joey Bada$$), the Underachievers and Flatbush Zombies.
East Coast is the Beast Coast. Fuck West may be Best but we Beast at everything and we taken over. With NY, Boston, Newark, Philly, D.C, Baltimore, Charleston, Atlanta, Montgomery, and Miami we are fucking awesome.
West may be best but Beast Coast runs this and we taken over the game.