While filming the movie, W.C. Fields regularly drank from a flask, which he insisted was only "pineapple juice." One day, however, the stagehands replaced the vodka in the flask with real pineapple juice. When Fields tasted it, he sputtered and shouted, "Who put pineapple juice in my pineapple juice?!"
Because of Fields' poor health during the filming of Poppy, Johnny Sinclair, his stunt double, in a plastic mask did all of his long shots and many of the shots in which Fields had to move quickly, crawl, etc. In fact, it is estimated that Sinclair did 75% of Fields' shots with Field's himself doing only 25%. Stills of Sinclair standing in for Fields were "embargoed" by the producers, but it is rumored that a few sneaked out of the studio.
W.C. Fields broke a vertebra during the filming and was in such pain that he fainted after walking out of camera range after filming the final scene.
One of over 700 Paramount Productions, filmed between 1929 and 1949, which were sold to MCA/Universal in 1958 for television distribution, and have been owned and controlled by Universal ever since; its earliest documented telecast took place in Boston Friday 19 October 1958 on WBZ (Channel 4); it first aired in Milwaukee Monday 4 May 1959 on WITI (Channel 6); it was released on DVD 20 March 2007 as one of 5 titles in Universal's W.C. Fields Comedy Collection Volume 2, and again 4 June 2013 as one of 10 titles in Universal's W.C. Fields Comedy Favorites Collection; it has also enjoyed an occasional airing on cable TV on Turner Classic Movies.
Prof. Eustace McGargle was W.C. Fields' most frequently performed role, having played it for 328 performances on Broadway in 1923 and in the silent movie Sally of the Sawdust (1925) before making this film version.