
Seizō Katō (加藤 精三, Katō Seizō; February 14, 1927 – January 17, 2014) was a Japanese actor, voice actor and narrator who worked for Haikyo (Tokyo Actor's Consumer's Cooperative Society).
Kato was born in Tokyo. He was noted for his role as Megatron and Galvatron from the 1st Transformers series until Transformers: The Headmasters. He also did the ADR for Takeshi Katō's character in Akira Kurosawa's Ran after the original actor had become injured.
He died of bladder cancer at a hospital in Itabashi, Tokyo on January 17, 2014 at age 86.
Description above from the Wikipedia article Seizō Katō, licensed under CC-BY-SA, full list of contributors on Wikipedia.

Crayon Shin-chan: The Hidden Treasure of the Buri Buri Kingdom
1994 · as BuriBuri Majin (voice)

Doraemon: Nobita's Dorabian Nights
1991 · as Abujiru (voice)

Detective Conan: The Raven Chaser
2009 · as Kiyonaga Matsumoto (voice)

Tokyo Godfathers
2003 · as Kaa-san (voice)

Doraemon: The Record of Nobita's Parallel Journey to the West
1988 · as Silver Horned King (voice)

Vampire Hunter D
1985 · as Count Magnus Lee (voice)

Denji Sentai Megaranger vs Carranger
1998 · as Helmedor

Doraemon: Nobita's Dinosaur
1980 · as Black Boy (voice)

Lensman
1984 · as Lord Helmuth (voice)

Kamen Rider Decade: All Riders vs. Dai-Shocker
2009 · as General Jark (voice)

Seijuu Sentai Gingaman vs Megaranger
1999 · as Gregory (voice)

Crayon Shin-chan: Unkokusai's Ambition
1995 · as Unkokusai (voice)

Twilight of the Dark Master
1997 · as Takamiya, male form (voice)

Crying Freeman 5: Abduction in Chinatown
1992 · as Larry Buck (voice)

OOO, Den-O, All Riders: Let's Go Kamen Riders
2011 · as General Jark (voice)

Lupin the Third: The Fuma Conspiracy
1987 · as Inspector Koichi Zenigata (voice)

Space Runaway Ideon: Be Invoked
1982 · as Gindoro (voice)

Kamen Rider: Run All Over the World
1989 · as General Jark (voice)