Robert Stack was 76 in Beavis and Butt-Head Do America when he played the character 'Agent Flemming (voice)'.
That was over 27 years ago in 1996.
In 2003 he died aged 84, starring in 69 films in his career, 9 of those after Beavis and Butt-Head Do America was first released. If he were alive today he would be 105.
In Beavis and Butt-Head Do America, I think Robert Stack looks: