Peter Cullen, the veteran voice actor renowned for his portrayal of Optimus Prime in the “Transformers” franchise and as Eeyore in the “Winnie the Pooh” series, died on August 26 at his home in Los Angeles. He was 85. The cause of death was not disclosed, according to his agent, Kevin Motley.

Cullen’s career spanned several decades, but he was most celebrated for giving voice to Optimus Prime, the heroic leader of the Autobots, a role he first assumed in the original 1984 animated series based on the popular toy line. Inspired by his brother Larry — a Marine veteran — Cullen developed the character’s distinctive voice, which combined strength and compassion. He later described his brother’s advice to be “strong enough to be gentle” as pivotal to shaping the tone he brought to the role.

The “Transformers” television series originally aired in syndication from 1984 to 1987. Cullen reprised the role across multiple formats, including subsequent animated series, video games, and the highly successful live-action films directed by Michael Bay in the 2000s, which significantly broadened the franchise’s reach.

Although Optimus Prime was killed off in the 1986 animated feature film, strong fan reactions led to the character’s revival in later episodes of the series. Cullen recounted being concerned about the character’s death when he first read the script, but the decision was reversed following audience feedback.

In addition to Optimus Prime, Cullen was also widely recognized as the voice of Eeyore, the melancholy donkey in “The New Adventures of Winnie the Pooh,” which aired in 1988 on ABC. He continued to voice the character in feature films, spin-offs, and other media, endearing himself to a younger generation of fans. Cullen said he enjoyed portraying Eeyore, appreciating the responses his portrayal elicited from children.

Born on July 28, 1941, in Montreal to American parents, Cullen was introduced to radio broadcasting at an early age through his maternal grandfather, Alfred Watterson McCann, a noted radio journalist. Cullen credited his upbringing on a farm with helping him develop his ability to mimic animal sounds, which contributed to his voice acting skills.

After graduating from the National Theater School of Canada in 1963, Cullen began working in Canadian theater and radio before moving to Hollywood. He found early success as an announcer on shows like “The Smothers Brothers Comedy Hour” and “The Sonny and Cher Comedy Hour.” His extensive voice-over work extended to series including “DuckTales,” “My Little Pony,” and the “Ghostbusters” television adaptation. Notably, he provided the uncredited guttural noises of the alien creature in the 1987 film “Predator.”

Cullen was nominated for a Daytime Emmy Award in 2011 for his performance as Optimus Prime in the animated reboot series “Transformers: Prime.”

He is survived by his children, Peter Cullen Jr. and Claire Ann Cullen. His brother Larry passed away in 2011. Additional details about his family were not immediately available. Throughout his career, Cullen remained closely connected to the qualities his brother inspired in his interpretations, making a lasting impact on fans around the world.