David Zen Mansley is an American theatrical and voice actor. He is best known for voicing of Agent/President John Bishop in the 2003 cartoon series Teenage Mutant Ninja Turtles. Mansley has also provided the voices for several other cartoon characters on TMNT such as Rat King, Darius Dun, Zog, Savanti Romero and Triple Threat. He has also provided the voice for Professor Armand Aniskov on the cartoon series Speed Racer: The Next Generation, Nefertari Nebra on the 4Kids version of One Piece and Lord Van Bloot on Chaotic.