It took me a long time to realize that Woltz was referring to Luca Brasi when speaking of the "goomba".
Tom Hagen brought him along to the studio.
Luca was the one who put the horse's head in Woltz's bed.
And Duvall is great when he's kidnapped by Solozzo.
"Your boss is dead."
Hagen comes close to tears, but then says:
"That may be true, but you can't stop Luca Brasi from coming after you."
"Well, let ME worry about Luca".
O/T, Robert Duvall doesn't look "older" because he's been bald since the early '70s.
He was wearing a hairpiece in the Godfather, and GF II.
He might have even been quite thin in To Kill A Mockingbird (1962), but I can't remember.
He here is from a 1965 episode, "Brass Ring", of the The Fugitive. Yes, Robert Duvall was definitely thinning then at the age of 34. He played the part of a paralyzed man and it was reminiscent of Boo Radley, something of a misunderstood outcast. I'll go way off topic to mention that having rediscovered The Fugitive recently, it was a well-written show from the standpoint of great dialog. It was far more involved than Dr. Kimble (David Jansen), as the hunted eluding the hunters, notably Lt. Philip Gerard (Barry Morse). Some fine actors appeared during its run and the dialog was invariably intelligent, giving the characters real dimension.