I remember watching a really dark fantasy cartoon as a kid, taking place in some alternate world with knights. I don't remember too much about the plot, but I remember the cover of the VHS was a picture of a blue or grey knightcreature sitting on a red or brown lizard or bird. It was kind of a "grown up" cartoon. Any ideas?

Wizards (1977) (http://en.wikipedia.org/wiki/Wizards_%28film%29)?

Yes! Thank you :D