I was gobsmacked to find this. I went on YouTube and searched under "Gershwin cartoons", knowing such an absurd thing could never be. And here he is in the Rhapsody in Blue segment from Disney's Fantasia 2000, obviously based on the famous Hirschfeld caricature of the 1930s:
I can't find Oscar Levant, but this fellow looks a little bit like him, especially the coffee:
But Oscar, of course, is infinitely sweeter. . .