[2] He is best remembered for voicing Dopey in Disney's Snow White and the Seven Dwarfs (1937) and for portraying Tylo in the Shirley Temple film The Blue Bird (1940).

[5] In addition to providing Dopey's vocalizations, Collins also recorded sneezing sounds for the film's chipmunk and squirrel characters.

After completing his work for the film, Disney wrote a letter to the casting director of 20th Century-Fox and Collins was put under contract to the studio.

Next to Dopey, Collins's most-beloved role is that of Tylo, a dog who is magically transformed into a human, in The Blue Bird (1940).

He died of a heart attack[6] in September 1940, age 57, just weeks after the premiere of his last film The Return of Frank James.