Which legendary director voiced Unicron in "The Transformers: The Movie"?

The answer is: Orson Welles

Orson Welles, the genius behind "Citizen Kane," closed out his legendary career by voicing a robot planet that eats other planets. He finished recording his lines as Unicron in 1985, just days before his death. The recording sessions must have been surreal. Here was Welles, one of cinema's greatest auteurs, reading lines about "universal greeting" and trying to wrap his head around what exactly a Transformer was.

The producers couldn't believe their luck in landing Welles, but they soon discovered he was mainly doing it for the paycheck. He had fallen on hard times and was taking basically any voice work offered.

Welles never saw the finished film. He passed away on October 10, 1985, before animation was completed. His final performance ended up being a mechanical space god who transforms into a planet and tries to eat Cybertron. It wasn't exactly "War of the Worlds," but there's something perfectly Wellesian about going out playing a larger-than-life character who literally devours worlds.

The film's sound engineers had to heavily modify Welles's voice in post-production because he was too weak to deliver the booming performance they wanted. The result was appropriately menacing. The man who once scared America with a radio broadcast about alien invaders had become an alien himself.