Batchick

Batchick is a superhero comic book series sold at The Android's Dungeon & Baseball Card Shop.

History
Batchick can be seen on a rack of comics when Bart and Milhouse are discussing the differences between  and Radiation Dude.

The cover contains a picture of a woman wearing a purple Batman-esque costume, with large bat wings on the back.

Behind the Laughter
The comic is a reference to the various female versions of Batman, most likely.