. . . . "River Styxx/merchandise"@en . . . . "River Styxx was trademarked on January 22, 2014 and her first doll came out in Mid November, 2014. As of January 01, 2015, her doll number totals 1 and makes up 0.29% of the entire Monster High doll collection. Other merchandise of her is not yet available."@en . . . . "River Styxx was trademarked on January 22, 2014 and her first doll came out in Mid November, 2014. As of January 01, 2015, her doll number totals 1 and makes up 0.29% of the entire Monster High doll collection. Other merchandise of her is not yet available."@en . . .