The Cosby Show Wiki. Rudy Huxtable. Rudith Lillian Rudy Huxtable (born September 27, 1979) is the youngest of the Huxtable children - only five years old at the beginning of the series, making her birth year 1979. She comes of age during the course of the show. The part of Rudy is played on the series by Keshia Knight Pulliam.