Neil Kaplan is the voice actor of Zarkon. He is known for his role as Optimus Prime from Transformers: Robots in Disguise, various roles in the Digimon franchise, and Madara Uchiha from Naruto.
The first day of recording for Zarkon was January 13, 2015 and that was also the first day that Kaplan met Bex Taylor-Klaus, with whom he shares a close friendship. Kaplan describes voicing Zarkon as voicing someone who is at ease, who does not fear for their life, doubt, or worry because they are at the top of a power structure. Hence, he does not voice Zarkon with any uneasiness to his voice or need to get loud very often. He does not believe modern audiences want a one-note villain, but rather a villainous character more complex and full of depth, and appreciates the changes made to Zarkon contrasting against his Defender of the Universe counterpart.
- Kaplan is of Jewish heritage.