A structure motivated by an impulse to slide over a surface, including: an impulse-receiving portion for receiving the impulse, the impulse-receiving portion defining a section of a generally semi-hemispherical structure and produced from a foam material patterned to represent at least a portion of a sports ball; and a sliding portion, coupled to the impulse-receiving portion, for sliding contact with the surface on a contact surface of the sliding portion responsive to the impulse the contact surface having a generally planar smooth surface having a periphery surrounded by an extension of the impulse receiving portion, wherein a tumbling of a coupled combination of the impulse-receiving portion and the sliding portion is inhibited by shifting a center of gravity downward by a greater weighting of the sliding portion relative to the impulse-receiving portion.