Who is considered the only leading actor in a network television series not to appear in the credits of the series in which he was the leading actor? The series was not one in the mists of early TV. It was in color, and some of the guest stars were Roman Gabriel, Patrick Macnee, Scott Glenn, Victor Buono, and George Takei.

Khigh Dhiegh ?Source

Exactly...but what took you so long?

(I have to admit that I thought this one would take at least a day or so. You're good, Mozart.)

Thanx to you for giving so much infos in your question.

I blame myself.