In the episode "Ride Me to Hell", Aldermach Maggotbone tells his daughter Callie that he's handing down the leadership and Slitherax to her. But in the end he switches to his assistant Cathy as the succeeding leader of Hell. Yet the ceremony for the passing of the demonic snake is interrupted by Francis Grimes and Slitherax escapes into a duct.
Slitherax later returns and crawls back down Aldermach's throat. And he continues as the leader of Hell.