>>57502
Based on those scraps of animation I would have imagined an intruder, or an entity hidden behind a curtain in the bathroom that first chops the sons's head off then the mothers. As a sequel I would have made a similar action happen at the beach or at a picnic in the woods. Didn't go any further because there aren't many people that can continue Chalk's work atm so I'd rather stick to some basic ideas.