Supernatural is an American television drama/thriller series created by writer and producer Eric Kripke, and was initially broadcast by The WB. After its first season, The WB and UPN merged to form The CW, which is the current broadcaster for the show in the United States. The show features two main characters, Jared Padalecki as Sam Winchester and Jensen Ackles as Dean Winchester, brothers who travel across the country in a black 1967 Chevrolet Impala to hunt demons, supernatural creatures, and other paranormal entities, many of them based on folklore, myths, and American urban legends. In addition, Supernatural chronicles the relationship between the brothers and their father, John Winchester, as they seek to avenge and understand the murder of their mother at the hands of the demon, Azazel. Supernatural has featured many other recurring guests that take part in story arcs that span a portion of a season. Occasionally, the recurring guest storylines will span multiple seasons. After the death of their father in the second season, the hunter Bobby Singer becomes a father figure to Sam and Dean.