Peter Cullen, the voice actor whose gravelly, gentle-giant baritone turned a toy-commercial robot into one of the most recognizable heroes in American pop culture, has died at 85. His family confirmed he passed away Wednesday at his home in Los Angeles, and his agent told Deadline that no cause of death has been disclosed.

Cullen first spoke as Optimus Prime, leader of the Autobots, in the original syndicated "The Transformers" cartoon that launched in 1984, and he never really put the character down. He reprised the role in Michael Bay's live-action franchise starting with 2007's "Transformers," then again in "The Last Knight," "Bumblebee" and "Rise of the Beasts," making him arguably the single most consistent voice in a 40-year toy-and-movie empire, according to The Hollywood Reporter.

In a statement shared with TMZ, Cullen's family said he "passed away peacefully, surrounded by his loving family — and held in the hearts of his many friends and countless fans worldwide," and asked that people honor him by "leading others with compassion, integrity, and loyalty" and remembering to "be strong enough to be gentle" — a line fans instantly recognized as pure Optimus Prime.

A career far bigger than one robot

Cullen, a classically trained Canadian actor and member of the first graduating class of the National Theatre School of Canada, built a decades-long career well beyond Cybertron. He voiced Eeyore in Disney's Winnie the Pooh properties for over 30 years, growled the vocal effects for the creature in 1987's "Predator," played Airborne and other characters across "G.I. Joe: A Real American Hero," and lent his voice to KARR on "Knight Rider" and Monterey Jack on "Chip 'n Dale Rescue Rangers," per a career rundown from Newsweek. He was passed over as Optimus Prime only once, for 2024's animated prequel "Transformers One," having spent much of that year still voicing the character in guest spots, including an appearance on Fox's "The Masked Singer."

"Be strong enough to be gentle." — Cullen family statement, echoing the character's signature philosophy

Tributes poured in from fans and industry figures within hours of the news breaking, with outlets from Variety to Forbes and CBR running remembrances of a performer many grew up hearing without ever knowing his face. Social media reaction leaned heavily on a shared sense of generational loss, with one recurring sentiment being some version of "my childhood is dying," as fans strung together recent losses among the voice actors and entertainers who shaped 1980s and '90s Saturday-morning television.

No public memorial has been announced. Hasbro, which owns the Transformers property, and Paramount, which produces the current film franchise, had not issued formal statements as of Thursday morning. Cullen is survived by his family; further details on services were not immediately available.