Robert A. Silverman is a Canadian actor cast five times by writer/director David Cronenberg. He is sometimes credited as Bob Silverman or Robert Silverman. Wikipedia
eXistenZ
Naked Lunch
Scanners
The Brood
125 Rooms of Comfort
Rabid
One Night Stand
The Ruining
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Jason X
Prom Night
984: Prisoner of the Future
Caressed
Waterworld
It Seemed Like a Good Idea at the Time