The Moomins (1978)

S1E6 New Guests

In the warmth of summer, Moominvalley is suddenly disrupted when anxious newcomers Fitslan and Totslan arrive, alarming the Moomins with the warning that the fearsome Mora is approaching. In a panic, everyone seals themselves inside their homes. When dawn breaks, the Mora descends upon Moominvalley, bringing with her a chilling layer of hoarfrost.