Question: Who produce the American Christmas fantasy in which Robert Prosky has a supporting act? 
Sentence (from "Gremlins 2: The New Batch"): It stars Zach Galligan, Phoebe Cates, John Glover, Robert Prosky, Haviland Morris, Dick Miller, Jackie Joseph, Robert Picardo and Christopher Lee; additionally, the film features Tony Randall and Frank Welker providing the voices for two gremlins.
Relevant evidence: No