The thing about elevator pitches is going to the bare, BARE minimum. Don't even bother with character names, just your gimmick and genre.
Here's the one for Splitting Image: A story about atonement in a magic kingdom, where an ex-villain tries to prove his potential for good. But not is all what it seems, and there are people who don't want him to change.
It's not the actual pitch I have written down (or exactly the one on the page) but it's the ideas that you need to keep on your head to present the comic as fast as you can, even if you forget how it goes and change the sentence around a dozen times. Speed and brevity is key, it's what it takes to get interest and talking about the whole story can come later.