'Leave It to Beaver' star Ken Osmond's cause of death revealed: report

“Leave It to Beaver” star Ken Osmond’s cause of death has been revealed.

According to the late actor’s death certificate obtained by TMZ on Monday, Osmond passed away after suffering cardiopulmonary arrest. He also had chronic obstructive pulmonary disease, which obstructs airflow from the lungs.

The death certificate also listed anemia, atrial fibrillation, congestive heart failure, depression, hypertension and pneumonia. It noted Osmond was a veteran of the United States Armed Forces with 60 years in the entertainment industry. The document also reported Osmond was cremated.

Osmond, who was best known for his role as Eddie Haskell on “Leave It to Beaver,” died May 18 at age 76 in his Los Angeles home surrounded by family.

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Ken Osmond is best known for portraying Eddie Haskell on the television sitcom, 'Leave It to Beaver.'

Ken Osmond is best known for portraying Eddie Haskell on the television sitcom, 'Leave It to Beaver.' (Photo by CBS via Getty Images)

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"He was an incredibly kind and wonderful father," Osmond's son Eric said in a statement obtained by Fox News at the time. ”He had his family gathered around him when he passed. He was loved and will be very missed.”

The Glendale, Calif., native started his career at age 4, working in commercials and as a film extra, and at age 9, he got his first speaking role in the movie "So Big," Variety reported. He went on to appear in "Good Morning Miss Dove," "Everything But the Truth," "The Loretta Young Show," "The Walter Winchell File," "Fury," "Lassie," and "Wagon Train," among others.

The actor starred in "Leave It to Beaver" from 1957 to 1963. Osmond's part as the two-faced teenage scoundrel, Haskell, was only supposed to be a one-off guest appearance. However, he did so well in his portrayal -- and the show's producers and its audience found him so memorable -- that he became a regular, appearing in nearly 100 of the show's 234 episodes.

Eddie was the best friend of Tony Dow's Wally Cleaver, big brother to Jerry Mathers' Beaver Cleaver. He constantly kissed up to adults and kicked down at his peers, usually in the same scene, and was the closest thing the wholesome show had to a villain. Viewers of all ages loved to hate him.

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Ken Osmond died in his Los Angeles home in May at age 76.

Ken Osmond died in his Los Angeles home in May at age 76. (Walt Disney Television via Getty Images Photo Archives/Walt Disney Television via Getty Images)

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Following the series' end, he reprised his role for the 1983 TV movie "Still the Beaver," as well as the revival "The New Leave it to Beaver," which ran from 1983 to 1989. According to Variety, his two real-life sons Eric and Christian played his sons in the '80s series. And in 1997, Osmond portrayed Haskell one final time in the film "Leave It to Beaver."

In 1970, Osmond joined the Los Angeles Police Department, according to Variety. Ten years later, he was reportedly shot during a chase but was saved by his bulletproof vest. He retired in 1988.

In 2014, he co-authored the memoir “Eddie: The Life and Times of America’s Preeminent Bad Boy.”

"Ken Osmond has been my lifelong friend and someone who I knew I could always go to for advice and good counsel,” Jerry Mathers told Fox News.

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Jerry Mathers (left) with Ken Osmond.

Jerry Mathers (left) with Ken Osmond. ((Photo by Walt Disney Television via Getty Images Photo Archives/Walt Disney Television via Getty Images))

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“I have always said that he was the best actor on our show because his real-life personality was so opposite of the character he so brilliantly portrayed,” the 71-year-old continued. “I will greatly miss him along with his countless fans all over the world."

According to Variety, Osmond is survived by his wife, Sandra, and his sons Christian and Eric.

Fox News’ Mariah Haas and The Associated Press contributed to this report.