John Henson, son of Muppets creator Jim Henson, suffered a heart attack and died on Friday, at the age of 48. Henson spent his life in the family business, performing as a child on shorts his father created for Sesame Street. As an adult, he helped run The Jim Henson Company, and, in the late 1980s, took over performing the oversized, gregarious monster Sweetums from Richard Hunt, who originated the character on The Muppet Show. As Sweetums, Henson performed on Muppets Tonight and in the movies Muppet Treasure Island and Muppets From Space.