Joe Otterson TV ReporterRussell Hornsby has been cast as Don King in the upcoming Hulu limited series about Mike Tyson, “Iron Mike,” Variety has learned exclusively.Hornsby joins previously announced series lead Trevante Rhodes, who will play Tyson. The series is said to be an exploration of the wild, tragic and controversial life and career of Tyson, one of the most polarizing figures in sports culture.