Lurch (The Addams Family) appearance, Lurch said, smiling, "He put me together." And another time in the original series where Lurch mentions his father wanted him to be a jockey (typically short and light people) instead of a butler. It was stated in "Addams Family Reunion" that Lurch is part Addams. This plays into his being a creation similar to Frankenstein's monster. The only definite body part that is from an Addams is his heart. Lurch's mother appears to be a physically normal, elderly woman, although she does not see anything unusual about the Addams family or their home, with the exception of Thing.
The Cat Who... does not appear to have any extraordinary abilities, so she does not play as active a role in solving the mysteries, but is still a major character in the series. She is also Siamese, and had a troubled past. Her history is fully explained in "The Cat Who Ate Danish Modern", but it can be summed up rather briefly. Qwilleran got Yum Yum as a kitten from the Taits, rich folk who did not treat Yum Yum properly and did not even truly decide on her name. Mr. Tait, a jade collector, named her Yu after a variety of jade,