Manfred is the son of Dutch immigrant Manfred Mugggs, who had dropped the third "G" from their surname when coming over to America. The younger Manfred married the future Mrs. Muggs and had a child, that they named Ethel. The Muggs family apparently lived a relatively comfortable upper-middle class life, being able to afford a home with a swimming pool and hot tub. Manfred, however, had the misfortune of investing money with Hiram Lodge, which cost them much of their savings. The Muggs planned to testify against Hiram at his hearing for embezzlement.
Throughout the SeriesEdit
Manfred and his wife were out of town briefly, leaving Ethel at home. This allowed Ethel, Betty Cooper, and Veronica Lodge to lure Chuck Clayton to the Muggs home, in order to force a confession from him regarding the sexual harassment of Ethel, Veronica, and several other girls.
Following the loss of their savings, Manfred and his wife argued constantly, which sent their daughter Ethel into a deep depression. When it became clear the Muggs would lose their home, Manfred attempted suicide by swallowing an entire bottle of sleeping pills, though he was hospitalized and treated.
Mrs. Muggs blamed Hiram Lodge for Manfred's suicide attempt, as did Hiram's own daughter Veronica.