A robot toy, having: a control unit formed by a portion of a body, wherein a form is changed by controlling the control unit, and a different movement is performed before and after the form change. Thereby, the robot toy which has various form changes and movement changes with high amusement can be realized. Also, in the drive device for a toy, one toy component is arranged on a link facing a frame in a four-section link, the other toy component is arranged on one of swinging links facing each other, the one of the swinging links extending to an opposite side with respect to the frame and a tip thereof rotatably and swingably engaging with a rotating disk at an eccentric position, and both toy components are rotated and perform opening and closing movements with each other by rotating the rotating disk, before or after the form change.