ARLINGTON, Texas–(BUSINESS WIRE)–Six Flags Entertainment Corporation (NYSE:SIX), the world’s largest regional theme park company and largest operator of water parks in North America, unveils Fright Fest Extreme – presented by SNICKERS, featuring an expansive lineup of terrifying horror franchises ahead of the brand’s highly anticipated annual event. Beginning September 7, thrill-seekers and horror enthusiasts are invited to immerse themselves in the pulse-pounding excitement and terror that o