21 December is the 355th day of the year (356th in leap years). There are 10 days remaining.
- The S.M.S.B. arrives at the NoHead Base just after midnight. The First Battle of the NoHead Base takes place.
- Paige is murdered by Sebiscuits.
- Mr. Stupid NoHead is defeated for the first time when he fails to murder Baby Intelligence.
- The Rocket army is temporarily deactivated.