Gregory Hines was cast as a last-minute replacement for then controversial comedian Richard Pryor, who had severely burned himself while freebasing cocaine.
The robe that Mel Brooks wore when he was portraying Moses, is the exact same robe that Charlton Heston wore when he played Moses in The Ten Commandments.
The Viking funeral gag was a Jewish in-joke, based on the libelous old myth that Jews had horns. (Making light of anti-Semitism has long been one of Mel Brooks' trademarks.)