And Jerry Lewis before them?
And the winner is:
http://en.allexperts.com/q/Classic-Film-2786/Multiple-Roles-2.htm
There have been many cases of multiple roles in films over the years. The most parts played award goes to Rolf Leslie, who played 27 parts in “Sixty Years a Queen” (1913).
Then, in descending order you have:
Lupino Lane - 24 parts in “Only Me” (1929).
Joseph Henabery - 14 characters in “Birth of a Nation” (1915).
Robert Hirsch - 12 roles in “No Questions on Saturday” (1964).
Michael Ripper - 9 parts in “What a Crazy World” (1963).
Eddie Murphy - 8 characters in “Nutty Professor II: The Klumps” (2000).
Eddie Murphy - 7 characters in “The Nutty Professor” (1996), Jerry Lewis having only played three characters in the original film in 1963.
Jerry Lewis - 7 characters in “The Family Jewels” (1965).
Peter Sellers - 6 roles in “Let’s Go Crazy” (1951).
Peter Sellers - 6 roles in “Soft Beds, Hard Battles” (1974).
Peter Sellers - 3 roles in “Dr. Strangelove” (1964) Mike Myers - 4 roles in “Austin Powers in Goldmember” (2002).
Terry Thomas - 3 parts in “Arabella” (1969).
Red Skelton - 3 characters in “Watch the Birdy” (1930).