Koroko is a six-sided cube Spectrobe that closesly resembles a gaming die. On its sides are four faces which represent different emotions: one side shows an angry face, another side shows a depressed face, the one after shows an indifferent face, and the last side shows a happy face. The top and bottom of the cube merely show intricate designs. The face that expresses anger is suggested to be its "front", but it will rotate to show the face that corresponds to the emotion it is currently feeling. Interestingly, if one pets a Koroko in the Incubator, it shows that it can shift and stretch at will.