Order and strict principles are vital to Mrs Fillyjonk. She doesn’t want her children to learn bad habits and gets worried if they play too boisterously. Mrs Fillyjonk wants her rules and principles to be obeyed to the letter.
Even the smallest misfortunes depress her and she easily loses her temper. Although Mrs Fillyjonk is dutiful to the point of tedium, deep inside she is perhaps a little jealous of how freely the Moomins live.
Mrs Fillyjonk is always giving her home and garden a thorough clean and tidy. She has a long snout, and wears a red dress and matching bobble hat. She also dresses all of her children in the exact same style. When she goes out walking with them, Mrs Fillyjonk carries a small handbag.
Mrs Fillyjonk lives with her three children in Moominvalley, in a house surrounded by a neat fence. She first appears in the picture book The Book About Moomin, Mymble and Little My.