Claptrap is celebrating his seventh birthday and wants you to hand out some invitations. Although it looks like the mission is timed, it is not for this part, so go talk to Moxxi, Scooter and Marcus. Return to Claptrap and the party will start, with the timer now beginning to count down. At two points the timer will stop, with the first time ordering you to eat some pizza and the second being to blow into the party favor. Eventually, the mission will end, so enjoy the spoils.