I actually spent nearly two weeks working on a new cartoon which was quite a bit longer than the one pictured above. But, after it was plagued with issues, and by the time it was finished, I decided a shorter setup to the same punchline would be better, and drew this instead. To see the eight pages I spent so much time drawing, click each of these links.
The gag in this cartoon is basically a synthesis of this picture and a conversation between Jerry and Elaine in an episode of Seinfeld, “The Bizarro Jerry,” in which Jerry explains the concept of Bizarro Superman to Elaine, telling her that he “says hello when he leaves, and goodbye when he arrives!” Elaine quickly pokes holes in the whole idea by pointing out that the opposite of goodbye would be “badbye,” and asking if Bizarro Superman lives underwater, or is black.
Oh, and, um, I do realize that Bizarros aren’t strictly evil twins, but I figured that would be accurate-enough and more easily read by people who aren’t familiar with the concept at all than the whole “perfect-imperfect opposite” thing.