Charles Ruttheimer the Second is father to Upchuck and a businessman of some success.
His first mention is in "Malled", where he let Upchuck borrow his gold card: "Dad wants me to pick up some bikinis for his secretary".
In The Daria Diaries, Upchuck hijacked his father's business voicemail while his father was abroad. When he came back, he had to record a new message apologising to his business associates and asking if they could "leave your name, number, and a brief description of what you feel would be an appropriate punishment for my son."
In "Children of the Scorn" by Kristen Bealer, he is part of Couples Therapy Night and has many good memories of Upchuck's childhood - most of them remembering something someone else did, to his son's bitter dismay.