Dr. Lewie's concept was based on a dream the creator had. In the dream, Dr. Lewie (who was unnamed) appeared as a young white mouse in an old movie similar to National Lampoon's Vacation. In the dream, there was a sequel to the movie which was also similar, however the mouse, who was apparently the brother of one of the main characters (who was a human) was older and was a dentist. He showed up in the house of his brother's family, and apparently in the dream, dentists brought bad luck. In the dream, he somewhat resembled Dr. Christopher Lewis from a really messed-up French movie titled Seducing Dr. Lewis (which the creator had recently seen in their French class).