Chikao Ōtsuka (July 5, 1929 - January 15, 2015) was a Japanese voice actor, as well as the father of Akio Ōtsuka. He was most well known for acting as the voice of Dr. Ivo Robotnik/Eggman and Professor Gerald Robotnik in the Sonic the Hedgehog franchise, Dr. Weil in the Mega Man Zero series, Tao Pai Pai from the Dragon Ball franchise, Wario from the Mario franchise, and acting as both the voice actor and dubbing actor for various incarnations of Captain Hook in various adaptations of Peter Pan.
Chikao Ōtsuka acted as the voice for Big Boss in Metal Gear Solid 4: Guns of the Patriots. Similar to in real life, Big Boss also acted as the "father" of Akio Ōtsuka's character, Solid Snake. He was chosen for the role by Hideo Kojima as a means to thaw the ice between the estranged father and son.
Although he does not have any roles in Super Smash Bros. Brawl either as a character from the Metal Gear series or any other characters of various franchises, he, or more accurately, one of his roles, is indirectly alluded to in the Codec conversation involving Sonic the Hedgehog. Snake (who in the Japanese version is voiced by Akio Otsuka) when contacted by Otacon mentions that he "for some reason doesn't like [Sonic]" and insists that he doesn't like him one bit when Otacon attempts to push the issue further. This refers to his father Chikao Ōtsuka's role as Dr. Eggman/Robotnik, Sonic's arch-enemy in the Sonic franchise.
Chikao Ōtsuka died from ischemic heart failure at age 85 on January 15, 2015.