Who originally did the voice for Shrek?

The answer is: Chris Farley. Not only had Chris Farley already been cast as the voice of the lead character in Shrek, he had completed most of the recordings for the film before suddenly passing away in 1997. He wasn’t able to fully complete all of the required dialogue, so they brought in Mike Myers. Myers was the one who came up with the Scottish accent. Boy, I’d love to see the movie with some of that original dialogue from the legendary Farley.Source