This Mean Girls t-shirt shows Karen Smith wearing mouse ears for Halloween. The shirt reads I'm A Mouse Duh!

In Mean Girls, Karen Smith is a member of a group of girls called the Plastics at North Shore High School. Karen is described at school as "dumbest girl you'll ever meet." On Halloween, Karen put on a pair of mouse ears, and when asked what she was supposed to be, she replied, "I'm a mouse, duh!"

Everyone will know you are a fan of the 2004 comedy starring Amanda Seyfried when you wear this I'm A Mouse Duh Mean Girls T-Shirt!