The drawing on folio 629v of the Codex Atlanticus bears the caption "Bird of the Comedy" and suggests that it is a theatrical effect, such as the Automobile or the Mechanical Lion.
The bird ran on a slightly inclined rope fastened to two opposite sides of a room. The bird's body served as a container for the internal mechanism consisting of a wheel and a pair of connecting rods that allowed the wings to move by simulating beating flight.