Wild, spasmodic but mostly very funny comedy, produced by, directed by, and starring that wayward comic genius Jerry Lewis.

It's a comic variation on the Jekyll and Hyde story, with Jerry cleverly going through a series of highly-coloured transformations that skilfully combines the fright with the fun, in his change from meek little professor to dashing debonair Buddy Love.

In the supporting cast, Stella Stevens is surely the most glamorous student any professor ever had. Jerry invents some side-splitting sight gags in this one, and even does a wicked impersonation of his old partner Dean Martin in what proved to be one of his greatest successes as a solo comic.

Lewis threatened for years to make a sequel, but it never happened: instead it was Eddie Murphy who remade the original.