The Cupcake Club is a club in Greg's local supermarket where anyone less then eight can join it and could take free cupcakes; Greg kept taking cupcakes even after he reached the age of eight.
One time, an alarm activated just as he bit into a cupcake, making Greg think that the alarm was caused by him taking a cupcake over the age of eight. This caused him to run out of the supermarket and several blocks further, where his mom eventually found him.
- In Rodrick Rules, and the rest of Cabin Fever, Greg had buck teeth (ressembling Manny) when he was little. But on the Cupcake Club card, Greg has four visible teeth.