I just watched a cartoon movie of the TMNT on TV called "Turtles Forever." It had the modern cartoon TMNT meet the classic cartoon TMNT. The contrast between the more serious modern turtles and the goofy classic turtles was funny. As well as the contrast between the modern alien/utrom Shredder and the classic imbecilic classic Shredder and Krang. Eventually there was a whole multiverse of TMNT revealed and images were shown from their various incarnations in tv, movies, video games and comics. At the end they went to the universe of the original grim-dark Eastman & Laird TMNT. Which was pretty cool. The world was black & white and those TMNT were grim, tough and narrated stuff. It was fun.