Bob Holt started his career in front of the cameras with a film role in 1950, playing Octavius Caesar in Julius Caesar followed by another role in 1959 in The Great St. Louis Bank Robbery. He moved on to primarily voice acting in 1968 providing all of the voices for a film short called Johnny Learns His Manners. Throughout the 1960's, 1970's, and 1980's, Bob provided voices for main and supporting characters in numerous animated television series and films including many based on the works of Dr. Seuss. Arguably the most enchanting work of this period was his providing the main voice in 1976 of Avatar in Ralph Bakshi's film Wizards and in the 1984 Joe Dante film Gremlins where Bob provided the voices of Mogwai and other various Gremlins. Bob past away from a heart attack on August 2, 1985. His last full performance, not including samples taken from previous projects, was as the voice of Rodney in The Adventures of the American Rabbit which was released in 1986 after his passing.