Peter Cullen’s Cause of Death Revealed

Peter Cullen, the legendary voice actor best known for voicing Optimus Prime in the Transformers franchise, has died at 85.

Cullen died last Wednesday at his home in Los Angeles, according to his death certificate obtained by TMZ. His cause of death was listed as cardiac arrest due to respiratory arrest. The certificate also listed malignant neoplasm of the lower lobe of the lung as an underlying cause, indicating lung cancer.

Cullen is scheduled to be buried at Forest Lawn on Sept. 9.

His family previously said he died peacefully, surrounded by loved ones. They also asked fans to honor his legacy by serving their communities with “compassion, integrity, and loyalty” and to remember the words, “be strong enough to be gentle.”

Cullen first voiced Optimus Prime in the original 1980s Transformers animated series and reprised the role in The Transformers: The Movie in 1986. He returned as the character for Michael Bay’s 2007 live-action film and every subsequent live-action installment through Transformers: Rise of the Beasts in 2023.

Beyond Transformers, Cullen was widely known as the voice of Eeyore in The New Adventures of Winnie the Pooh and other Disney productions. He also provided the voice of King Kong in the 1976 film King Kong and vocal effects for the Predator in the 1987 film Predator.

In 2023, Cullen received a Lifetime Achievement Award from the National Academy of Television Arts & Sciences at the Children’s & Family Emmy Awards.

During his acceptance speech, Cullen said Optimus Prime was inspired by his late brother Larry, a decorated U.S. Marine Corps captain. He recalled his brother telling him, “Peter, if you’re going to be a hero, be a real hero. Be strong enough to be gentle.”

Cullen ended the speech by saying, “Semper Fi, Larry. All my heart, I thank you.”