Mark Hamill, the voice behind many iconic characters in pop culture is now going from Gotham to New York City, when he lends his voice to a new character on The Teenage Mutant Ninja Turtles.
Not much is known about the character he will voice in the 5th season of TMNT but we do have the name of the character and some concept art. Here is Kavaxas: Demodragon of the Underworld.
The character looks to be some sort of demon/dragon/reptilian hybrid and coincidentally, somewhat resembles Star Wars villain, Darth Maul.
Source: TMNT Tumblr