Dreyfuss admits he faced his fears daily on the set - because Shaw was such an intimidating presence.
He tells WENN, "Robert totally intimidated me. I knew that on the first day I met him. I knocked on his dressing room door and I said, 'I have to say this before anything else happens - your Claudius was the best Claudius ever,' and then we started the relationship.
"Having not said that, I would've spent the entire summer going, 'Eek.' He terrified me.
"But he made me laugh and he was a great gentleman. He was also a terrible bully and he was really big."