Malcolm-Jamal Warner, the actor, who has died aged 54, was cast as Theo Huxtable in the sitcom The Cosby Show at the age of 13, and over the course of some 200 episodes became one of US television’s best-known teenagers.

The actor, who died Sunday at 54, was best known for his role as Theo Huxtable, the only son of Cliff and Clair Huxtable, who was based on creator Bill Cosby's son.

Keshia Knight Pulliam is paying tribute to her late Cosby Show costar, Malcolm-Jamal Warner. The actress, who was only six years old when she first starred as Rudy Huxtable on the sit-com, remembered her “big brother” in a poignant Instagram post a week after he tragically drowned at 54.