When does Metalocalypse return?

Metalocalypse is an American musical adult animated television series. It was created by Brendon Small and Tommy Blacha for Adult Swim. It premiered on August 6, 2006, and was canceled in 2013. In the series, Dethklok is a death metal band that enjoys a level of popularity unheard of in reality, ranking as the seventh-largest economy on Earth by the end of the second season.