'Transformers' Voice Actor Peter Cullen Dead at 85

Peter Cullen, famous for voicing Optimus Prime in the 'Transformers' franchise, is dead.

The legendary voice actor's agent tells TMZ ... Peter died Wednesday at his Los Angeles home.

The cause of death is unclear.

Peter's family tells TMZ ... "Peter Cullen passed away peacefully, surrounded by his loving family - and held in the hearts of his many friends and countless fans worldwide. His family asks that you honor his remarkable legacy by serving your communities and leading others with compassion, integrity, and loyalty and always remember 'be strong enough to be gentle.'"

Peter voiced Optimus Prime, the leader of the Autobots, in the original 1980s "Transformers" animated TV series ... and returned to the role in the Michael Bay film series.

In the first "Transformers" movie, Peter gives an iconic speech as Optimus Prime in the final scene.

Peter is also known for voicing Predator in the 1987 "Predator" film.

He was Eeyore in 'Winnie The Pooh' and Monterey Jack in "Chip 'n Dale Rescue Rangers," plus KARR in "Knight Rider" ... and on and on.

Peter was even the voice of Mario in the original "Donkey Kong" animated series way back in the 1980s.

He was 85.