Makoto Iwamatsu (岩松 信, Iwamatsu Makoto) (December 10, 1933 – July 21, 2006), professionally known as Mako Iwamatsu or just Mako, was a Japanese-American actor and voice talent, nominated for the Oscar and Tony awards. He is best known for roles in the Arnold Schwarzenegger Conan movies, Highlander III, and the Jackie Chan film Big Brawl, as well as the voice of main villain Aku in the cartoon Samurai Jack also for playing Iroh in Avatar: The Last Airbender.
Director Kevin Munroe announced on July 20, 2006 that Mako was voicing Splinter in the then-upcoming 2007 film, TMNT. Sadly, the very next day, Mako passed away at the age of 72. All of Mako's lines for the film had been finished, and any ADR cleanup was finished by Greg Baldwin.