Zeppo Marx Biography
The youngest of the Marx Brothers, Zeppo was put into the role of the straight man after his brother Gummo left the act. Zeppo also acted as an understudy to all three of his brothers, and he has been said to have played Grouchos part better than Groucho himself. After playing small parts in the first five Marx Brothers movies, Zeppo felt his talent wasn't being used to its full extent and left the act to join Gummo as an agent. Somewhat of a mechanical whiz, Zeppo invented a wristwatch that would monitor the pulse rate of cardiac patients, and his company, Marman Products, produced clamping devices which were used in the first atomic bomb raids over Japan in 1945. Zeppo died on November 30th, 1979 from cancer.
Trivia

Brother of Groucho Marx, Chico Marx, Harpo Marx, and Gummo Marx.

Brother-in-law of Eden Hartford, Ruth Johnson, Kay Marvis, and Susan Fleming.

Throughout his life, he had many careers including inventor, talent agent, manufacturer, commercial fisherman, and grapefruit grower.

In real life, he was supposedly the funniest of his brothers despite always playing the straight man in their films.

He was a serious amateur machinist, and among the products his company, Marman, developed in the late 1940s was a 2-cylinder motorized bicycle, the Marman Twin (produced 1948-49). Unfortunately, his bike was unable to compete with the more established Whizzers, despite being far more powerful. These bikes are highly collectible today.

Since he'd missed out when his brothers received their nicknames, he was given one by his siblings. He was always practicing acrobatics, so he was named "Zippo" -- after "Mr. Zippo," the star of a well-known chimpanzee act. Feeling it was unflattering, he insisted it be Zeppo. Another version of this story , was that his name was changed to "Zeppo" in honor of the then popular "Zepplin".

At the time of his death, he was the last surviving of The Marx Brothers.

When he married Barbara Marx, her son, Bobby Oliver, took the Marx surname, although Marx never legally adopted him.

Officially left the brothers' comedy team to become an agent on March 30, 1934.
Source provided by imdb (Copyright) - The Internet Movie Database.