In lighting for film, theatre and still photography, a cucoloris (occasionally also spelled cuculoris, kookaloris, cookaloris or cucalorus) is a device for casting shadows or silhouettes to produce patterned illumination. It is normally referred to as a cookie or sometimes as a kook or a coo-koo. The cucoloris is used to create a more natural look by breaking up the light from a man-made source. It can be used to simulate movement by passing shadows or light coming through a leafy canopy.