His career as a voice artist started with the 1968 short film Johnny Learns His Manners , for which he provided all of the voices .
Holt 's first film role came in 1950 , acting as Octavius Caesar in Julius Caesar .
Holt 's career as a voice artist started with the 1968 short film Johnny Learns His Manners , for which he provided all of the voices .
Holt 's first film role came in 1950 , acting as Octavius Caesar in Julius Caesar .