It is a little known fact that Saturday Night Live funnyman Chris Farley was the original actor cast as the voice of the title character in the 2001 DreamWorks animated film Shrek. According to the Jim Hill Media website, the plot with Farley on board was somewhat different than what ended up on film. "It was about a teenage ogre who wasn't all that eager to go into the family business. You see, young Shrek didn't really want to frighten people. He longed to make friends, help people. This ogre actually dreamed of becoming a knight". Those involved with recording Farley labelled it as one of his best performances.
Unfortunately, with about 95% of the film's dialogue finished (his role included), Farley died from a drug overdose on December 18, 1997 at the age of 33, still working on the film just a week before his death. There were talks of having a vocal impersonator brought in to record the remaining lines, but ultimately, fellow SNL cast member Mike Myers was hired and the script was re-written, becoming the Academy Award*-winning film we know and love.
The studio has not released any of the original Farley audio, and nothing has been heard of it by the public.
(*For Best Animated Film)