Mr. Spock, meet Sentinel Prime.

Leonard Nimoy is joining Paramount's "Transformers: Dark of the Moon" as the voice of Optimus Prime's predecessor, Sentinel Prime, reports Entertainment Weekly.

The character is glimpsed in the film's trailer, slumbering on the moon as Apollo 11 astronauts explore the alien wreckage. In the film, Sentinel will transform into a fire engine to do battle with the evil Decepticons.

Hugo Weaving and vocal vets Peter Cullen and Frank Welker are among the film's other voices. The live-action cast includes returning star Shia LaBeouf, John Turturro and Josh Duhamel, plus newcomers John Malkovich, Frances McDormand, Patrick Dempsey and Victoria's Secret model Rosie Huntington-Whiteley.

"Star Trek" legend Nimoy was also the voice of Galvatron in 1986's animated "Transformers: The Movie," which also featured the voices of Orson Welles, Eric Idle, Robert Stack and, um, Judd Nelson. He made a cameo appearance, reprising his iconic role as Spock, in J.J. Abram's 2009 "Star Trek" reboot.


"Transformers" director Michael Bay ("Bad Boys," "Pearl Harbor") told EW he had wanted to cast Nimoy, but "was too scared to ask him." "Plus," he continued, "he’s married to Susan Bay, who’s a cousin of mine. So I had to be careful. I’ve met him at family functions. But he told me, 'I would be honored. I’m glad to be back!'"

"Transformers: Dark of the Moon" opens in 3D on July 1.