James Tynion IV and Freddie E. Williams II's Batman/Teenage Mutant Ninja Turtles crossover was one of the best comic books of the year, and if you doubt that, consider that there was a scene where Shredder and Ra's Al-Ghul used mutagen on Batman's enemies and turned Mr. Freeze into a polar bear. If you can think of a comic where something better than that happened, then folks, I want to hear about it.
The only downside was that it ended after only six issues. Now, though, it looks like we're going to get a sequel --- sort of. Today at San Diego Comic-Con, IDW and DC announced Batman/TMNT Adventures, a second crossover between the Dark Knight and the Heroes in a Half-Shell --- and this time, it's set in the animated universes of both characters.