I started sketching something that kinda looked like Humpty Hump, so I went with it. Back stories are awesome...
My favorite of the Mario Bros - not including seldom seen older brother 'Phil.' Actually - that's not a bad idea. Draw a third Mario brother who never got any public attention and works as an accountant or something. Kind of like the third Manning brother. I don't think anything I wrote just makes sense, but regardless, I like Luigi.