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

Cullen died on Wednesday at his home in Los Angeles, his agent, Kevin Motley, confirmed to the Los Angeles Times on Thursday.

His cause of death was not disclosed.

His family said he “passed away peacefully, surrounded by his loving family — and held in the hearts of his many friends and countless fans worldwide.”

“Honour his remarkable legacy by serving your communities and leading others with compassion, integrity, and loyalty and always remember ‘be strong enough to be gentle,” the family asked fans.

Cullen, whose career spanned television, films, video games and theme park rides, amassed more than 200 credits.

His other roles included the giant ape in the 1976 remake of King Kong, the villainous vehicle KARR in the Knight Rider television series and the voice of the alien hunter in the original Predator film.

However, Cullen was best known for his work in animation and children’s programmes, particularly during the 1980s and 1990s.

He originated the role of Optimus Prime in the 1980s animated Transformers series, known among fans as “G1” or “Generation 1”.

He also voiced the character in The Transformers: The Movie (1986).

When the franchise moved to live action with Michael Bay’s 2007 film Transformers, Cullen returned to voice Optimus Prime.

He reprised the role in Transformers: Revenge of the Fallen (2009), Transformers: Dark of the Moon (2011), Transformers: Age of Extinction (2014) and Transformers: The Last Knight (2017).

He also voiced Optimus Prime in the 2018 prequel Bumblebee and Transformers: Rise of the Beasts (2023).

Cullen also voiced Eeyore, the pessimistic donkey in Winnie the Pooh. He first played the character in The New Adventures of Winnie the Pooh, which aired from 1988 to 1991.

He continued as Eeyore in several other productions, including The Tigger Movie (2000), Piglet’s Big Movie (2003) and The Book of Pooh series.

Cullen was nominated for a Daytime Emmy for his work as Optimus Prime in Transformers: Prime in 2011 and received a Lifetime Achievement Award at the Children’s and Family Emmy Awards in 2023.

Born Peter Claver Cullen on July 28, 1941, in Montreal to American parents Henry and Muriel Cullen, he was one of four children.

He graduated from the National Theatre School of Canada in 1963 and later performed Shakespeare in Stratford, Ontario, before joining the repertory company at Toronto’s Crest Theatre.

Cullen is survived by his four children, Angus, Claire, Pilar and Clay, according to the Associated Press.