Roddy McDowall

McDowall began acting as a child in Britain before relocating to Hollywood during World War II, where he successfully transitioned from a beloved child star into one of the industry's most respected character actors.

He spent hours in ape makeup to play the chimpanzee archivist Cornelius — and became so identified with the franchise that he returned across multiple sequels and the TV series. He underwent hours of makeup application for nearly every day of shooting, communicating almost entirely through his eyes and voice beneath the prosthetics.

He remained closely tied to the franchise for the rest of his career, and the transformation required to play the role is still cited as a landmark achievement in makeup effects history.