The Addamses are a close-knit extended family with decidedly macabre interests. They are humans with supernatural abilities. No explanation for their powers is explicitly given in the series. The very wealthy, endlessly enthusiastic Gomez Addams is madly in love with his refined wife Morticia. Along with their two children, Wednesday and Pugsley, Uncle Fester and Grandmama, they reside in an ornate, gloomy, Second Empire style mansion, attended by their servants, Lurch, the towering butler, and Thing, a hand that usually appears out of a small wooden box. Occasionally, episodes would feature relatives or other members of their weird subculture, such as Cousin Itt or Morticia's older sister, Ophelia.

Source: Wikipedia.org