Sasheer Zamata has been cast for Marvel's upcoming WandaVision spinoff series, Agatha: Coven of Chaos. Her character has been kept under wraps, but she will be joining Kathryn Hahn who plays the lead character of Agatha Harkness. Agatha - Coven of Chaos: Marvel's WandaVision Spinoff Series Casts Sasheer Zamata.