The series is the final part of Machinima's and Hasbro's Transformers: Prime Wars Trilogy that started with Combiner Wars and then Titans Returns which concluded on Tuesday. The animated series airs on Verizon's streaming service go90.
Hamill, who previously voiced a character in Transformers: Rescue Bots in 2014, will be portraying Decepticon Megatronus who was exiled from the Transformers' home planet of Cybertron after killing one of the original Thirteen Primes, noted The Hollywood Reporter.
Joe, meanwhile, will be taking on the role of Predaking. "Very happy to announce I am joining the cast of the new Transformers animated series. #PredaKingLives #transformers," the WWE Superstar said on Twitter.
Hamill and Joe will also be joined by Ron Perlman who will be portraying Optimus Primal along with Mikey Way, Jaime King and Gregg Berger who voiced Grimlock in 1986's Transformers: The Movie. Series veterans Wil Wheaton, Judd Nelson and Kari Wahlgren are also returning.
Transformers: Power of the Primes is scheduled to debut in the second quarter of 2018.