There's a famous gag that a camel is a horse that was designed by a committee. Murders in the Zoo is a good, creepy early '30s thriller with one design flaw so wrong as to sink the whole thing. Every thriller has a little comic relief character. In this one it's the zoo's publicist who is afraid of animals. But somebody came up with the bright idea of casting Charlie Ruggles in this role. Now Ruggles is basically a one-note comic actor who inexplicably attained name-above-the-title stardom. And with his name in the cast, suddenly this supporting role became the starring role. You can see all the places where scenes were added or expanded to give the character more screen time. But he is still just the comic relief--he is not involved in any way with any major development in the storyline. He could be excised completely and never be missed. Randolph Scott is the hero and Lionel Atwill the villain, and both acquit themselves admirably. But every few minutes the forward movement of the story comes to a screeching halt while we are treated to the antics of the "star", and so the poor camel never quite gets his gait. The film has some genuinely classic "horror movie" moments, but it would be so very much better with a reliable character man providing the "comic relief" instead of making this relatively insignificant role into a star turn (for ANY star).
Review of Murders in the Zoo
