As you're taking pop from a 12 pack in the fridge, you notice something brown rolling in the carton. No big deal. As you're removing the last can, the brown thing rolls forward and appears to be a petrified insect cocoon of some sort. What would you do?

Cherry Diet Dr. Pepper, and it had been stored at the house for a while after purchase/before refrigeration.

From the size, I’d say it probably had to have developed in the carton (not fallen in), and there was some discoloration inside the cardboard carton.