Today is a sad day, for Haruo Nakajima has left us. For those unfamiliar, he was the man in the monster suit from Godzilla King of the Monsters (1956) through Godzilla vs. Gigan (1972), bringing a cultural icon to life as he tore down cities, fought monsters and kicked Kilaak ass. That'd be ten films in total. He also played Rodan, Varan, Baragon, a giant robot in The Mysterians (1957), a giant walrus in Gorath (1962), a killer mushroom in Mantango (1963), a Gargantua, and one of the goofiest version of King Kong of ever in King Kong Escapes (1967).
As to whether he should be designated as an actor or a stuntman or suit specialists, I think the correct answer is all of the above. He was a legend. He was my hero. He was Godzilla. And he was and will forever be one of my favorite attractions on the big screen. Thanks for bringing the Big Guy to life for all those years. Sayonara, Nakajima-san.