What was the last Marx Brothers film to feature Zeppo?

The last Marx Brothers film to feature Zeppo was Duck Soup. Zeppo Marx was a part of the Marx Brothers comedy team in their earlier films, but by the time Duck Soup was released in 1933, he had left the group to pursue other ventures. Although Zeppo's role in Duck Soup was quite small, his departure marked the end of an era for the Marx Brothers as a full ensemble.