TRANSFORMERS THE LAST KNIGHT Blu-ray Interview with Peter Cullen and Frank Welker During a special press day for the Blu-ray & Digital release of TRANSFORMERS: THE LAST KNIGHT, I had the privilege of interviewing the beloved voice talents of Peter Cullen (Optimus Prime) and Frank Welker (Megatron). TRANSFORMERS: THE LAST KNIGHT is now available on Digital & Blu-ray/DVD Combo Pack! Optimus Prime finding his home planet, Cybertron, now a dead planet, which he comes to find he was responsible for killing. He finds a way to bring the planet back to life, but in order to do so he needs to find an artifact, and that artifact is on Earth .