Van wie was Rolf Sirnes?

Earle Hyman (born George Earle Plummer; October 11, 1926 – November 17, 2017) was an American stage, television, and film actor. Hyman is known for his role on ThunderCats as the voice of Panthro and various other characters. He also appeared on The Cosby Show as Cliff's father, Russell Huxtable. Singer Phyllis Hyman was his cousin.