An Episcopal priest and private school headmaster who has been waging a successful one-man campaign to get advertising withdrawn from a Fox sitcom called ''The Family Guy'' said yesterday that he had begun the crusade out of annoyance that a colleague's surname was chosen for the show's unruly leading family.

But the Rev. Richardson Schell said he pursued his extensive letter-writing campaign to advertisers -- in the name of a group called Proud Sponsors USA that he admits does not exist -- strictly because of what he called ''obnoxious, objectionable content'' in the animated show.

''The Family Guy,'' about a dysfunctional Rhode Island family named Griffin, was created by Seth MacFarlane, a 1991 graduate of the Kent School in Kent, Conn., which Father Schell has led for 18 years. The collisions between fact and fiction go on from there.

Father Schell's longtime assistant, Elaine Griffin, was a family friend of the MacFarlanes, and Mr. MacFarlane's mother, Perry, worked at the school for 15 years before resigning this spring after an argument with Father Schell over his objections to her son's use of the Griffin name.