CRANKY FACE: Angry Lego faces could have a significant impact on how children play. Angry Lego faces could have a significant impact on how children play, a University of Canterbury robot expert says.

In good form, the face has a simple switch—from good to evil, happy to angry. Or, as [Jens] designates the modes: “Fren” and “Not Fren.” [Jens] does a great job explaining the build ...