One voice could rally a convoy of giant robots and, softened to a sigh, speak for a gloomy donkey. Peter Cullen, the Canadian actor whose Optimus Prime led Transformers across television, films and games and whose Eeyore colored Winnie the Pooh stories for decades, died at 85 on August 26 at his Los Angeles home, his agent told The Hollywood Reporter.

The authority in Optimus Prime began with an older brother, not a machine. When Cullen prepared to audition in 1984, he thought of Larry Cullen, a decorated United States Marine who had returned from Vietnam quieter and more deliberate. Larry told him that a real hero did not need to shout and was "strong enough to be gentle." Cullen lowered his voice, carried that composure into the booth and found the sound that became inseparable from the Autobots' leader. The account, preserved in the National Academy of Television Arts and Sciences program honoring Cullen, explains why his most famous performance conveyed protection as much as power.

Peter Claver Cullen was born in Montreal on July 28, 1941, one of four children of Henry and Muriel Cullen. Long before a microphone became his workplace, he tested his range on the cows and chickens of a neighboring dairy farm, trying accents and speeches to see whether the animals would turn toward him. An English teacher encouraged the same instinct through recitation and Shakespeare. Cullen completed the Acting program at the National Theatre School of Canada in 1963 as a member of its first graduating class, then studied with operatic coach Bernard Diamant, performed Shakespeare in Stratford, Ontario, and joined Toronto's Crest Theatre repertory company.

His first professional years asked him to be seen as well as heard. He announced at Montreal radio station CKGM, played an astronaut on the children's series The Buddies and supplied a collection of characters for live Canadian television. A friendship with comedian Jonathan Winters helped bring Cullen to the attention of Hollywood producers. He moved his young family to California in 1971 and appeared in sketches and announcing roles on variety programs associated with the Smothers Brothers, Sonny and Cher, and the Hudson Brothers.

The decisive turn came when voiceover agent Steve Tisherman urged Cullen to concentrate on recorded performance. Commercials, trailers and animated television followed. By the early 1980s he had learned how little a microphone required and how much a character could gain from restraint. That craft met its ideal role in The Transformers. Cullen voiced both Optimus Prime and Ironhide in the original syndicated series, beginning in 1984, and carried Optimus into the 1986 animated film. Children heard a commander whose strength rested in patience, duty and an unmistakably human warmth.

The role survived changes in format, audience and technology. After a long interval, fan demand helped return Cullen to Optimus for the 2007 live-action Transformers film. He continued through the sequels and related films, including Bumblebee and 2023's Rise of the Beasts, while also voicing the character in later television series and games. In 2024, Hasbro brought Cullen, Frank Welker and other original cast members together for a table read celebrating the animated show's fortieth anniversary, a reunion described by Hasbro as the first such collaboration in decades.

Eeyore demanded almost the opposite musical register. Cullen began the role on The New Adventures of Winnie the Pooh in 1988 and continued across later Disney projects. He did not simply imitate an earlier interpretation. Seeing the animation, he chose tenderness over roughness. "I made him lighter, softer, kinder, gentler, but still deep," he later said. That gentleness gave the character's gloom a cushion and showed the breadth hidden inside the actor's famously resonant lower range.

His catalogue stretched well beyond those two signature characters. Cullen voiced the cheese-loving Monterey Jack in Chip 'n Dale: Rescue Rangers, Mario in Saturday Supercade, and characters in both Lion Voltron and Vehicle Voltron. He supplied King Kong's vocal work for the 1976 remake, gave the automated vehicle K.A.R.R. its cold precision on Knight Rider and devised the alien Predator's clicking sounds for the 1987 film. Whether the assignment called for a heroic speech, a mechanical intelligence or a creature without language, he built the performance from rhythm, texture and the image in front of him.

Recognition arrived from the industry that had heard his range for decades. His work as Optimus on Transformers Prime brought a 2011 Daytime Emmy nomination. In 2023, longtime colleague Frank Welker presented him with the Children's & Family Emmy Lifetime Achievement Award. The honor joined two performers whose rivalry as Optimus and Megatron concealed a durable creative partnership.

Cullen also put Optimus Prime's cultural reach to work outside entertainment. He addressed students at the 2012 NASA Optimus Prime Spinoff Video Contest at Kennedy Space Center and later met young inventors through the agency's OPSPARC challenge. At a 2017 gathering, he recorded videos with winning teams and called them a team of heroes. NASA reported that the program connected the Transformers character with student designs based on public space technology.

He was survived by his children Angus, Claire, Pilar and Clay. Their father's recordings remain woven through Saturday morning animation, theatrical sound systems, games and Disney stories. Optimus Prime still speaks with Larry Cullen's quiet model of heroism. Eeyore still answers sadness with a low, gentle murmur. The roars, clicks and comic voices reveal the same disciplined actor who began by testing sounds at a neighboring dairy farm, then spent more than six decades showing how much character could live in a breath.