When the man dies, it is discovered that his last will and testament made Rhubarb his sole beneficiary; hence the cat inherits the baseball team.

His fiancée Polly Sickles (Jan Sterling), daughter of the team's manager (William Frawley), is terribly allergic to Rhubarb, causing many problems.

And when the team's players discover they are owned by a cat, they stage a protest until Yeager persuades them that Rhubarb brings them luck.

Brooklyn's fortunes turn for the worse while the search for Rhubarb goes on, until the cat finally escapes from his captors and races to the ballpark to save the day.

There was no interest in the project for two years, then film rights were bought by Arthur Lubin who had just made Francis the Talking Mule and was looking for another animal story.

[10] In September the film was assigned to a production unit at Paramount run by William Perlberg and George Seaton.

William Frawley began portraying "Fred Mertz" in the I Love Lucy television series with Lucille Ball and Desi Arnaz initially broadcast two months after the release of Rhubarb that same year.

[1] The New York Times said the film had "a lot of good natured chuckles" but also "some arid stretches and the humor is seldom as sharp as it was in the book.

"[17] Diabolique magazine wrote "There are some funny moments though the director can’t overcome the main problem of all live action movies about cats – namely, their personality doesn’t come across screen.

There’s no strong relationship between Rhubarb and Ray Milland so the film feels hollow at its core in a way the Francis movies never did.