The Kid with the Clock in his Forehead is Von Tock one of Baron Klaus Wulfenbach's juvenile wards, although whether he is a regular student, student/hostage or progeny of some of the staff or crew on board the Castle Wulfenbach is unable to be determined. That being said, he seems to be fairly canny with a fair eye for avoiding trouble, as he remains calm in the face of Von Pinn's displeasure with Agatha Clay when the younger children are set to wailing, but later accuses Agatha, "Sleipnir "Someone who may be his older brother or cousin (there's something of a family resemblance, although the hair is more ginger) seems to be in service to the empire, in that DuMedd for optical signalling back to the Castle Wulfenbach and the Baron.
What, if any, biological function the clock may serve goes unexplained at this time; they may be adopted servitors from a Sparky family of procrastinators who were attempting to better themselves by constant reminders of the current time; or they may be the Sparky family of procrastinators themselves taking some self-responsibility. Perhaps the Secret Blueprints, Vol. II will reveal the truth.