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
D'Arcy Nader
Naked Lunch
Hans
Scanners
Benjamin Pierce
The Brood
Jan Hartog
125 Rooms of Comfort
Rabid
Man in Hospital
One Night Stand
Nick
The Ruining
Henry
Partners
Hayes
Jason X
Dieter Perez
Prom Night
Mr. Sykes
984: Prisoner of the Future
Prisoner
Sweet Substitute
Al
Waterworld
Hydroholic
It Seemed Like a Good Idea at the Time
Lawyer
Winter Kept Us Warm