One of Mortimer's aunts who appears benevolent and caring but harbors a peculiar secret with her sister, Martha.

Abby's sister and Mortimer’s other aunt, who shares a close bond and a secretive past with Abby, contributing to the household’s unusual activities.

Mortimer's brother, whose menacing presence and criminal activities generate tension within the Brewster household.

A timid plastic surgeon who aids Jonathan by altering his appearance, contributing to his efforts to evade capture.

Mortimer's fiancée, whose relationship with him contrasts with his chaotic family life, providing a glimpse of normalcy and support.