Before he became Roy Roger's horse, "Trigger," in which feature film did he appear?

Golden Cloud (later to be renamed Trigger) made an early appearance as the mount of Maid Marian, played by Olivia de Havilland in 'The Adventures of Robin Hood' (1938).

Trigger (originally named Golden Cloud, July 4, 1934 – July 3, 1965) was a 15.3 hands (63 inches, 160 cm) palomino horse made famous in American Western films with his owner and rider, cowboy star Roy Rogers.

Trigger was born in San Diego, California. Though often mistaken for a Tennessee Walking Horse, his sire was a Thoroughbred and his dam a grade (unregistered) mare who, like Trigger, was a palomino. Movie director William Witney, who directed Roy and Trigger in many of their movies, claimed a slightly different lineage, that his sire was a "registered" Palomino stallion, though no known Palomino registry existed at the time of Trigger's birth, and his dam was by a Thoroughbred and out of a "cold-blood" mare. Though Trigger remained a stallion his entire life, he was never bred and has no descendants.