I don’t quite understand why took me too long to spot THIS:
If you look into the picture, among the load of alternate versions of Darkwing Duck (in what seems to be a parody of “Crisis on Infinite Earths”) you can spot a Roger Rabbit-looking Darkwing Duck wielding nothing less than the singing sword! Then, you can catch some other references to various movies, cartoons or comics which are enough to keep you busy for a while.
I found this interesting vignette on Captain Comics’ forum, specifically on this discussion. Even you can find another extract from the same comic issue, in which you can spot several more parodies of well-known characters. Worth the read!