This paper presents a novel Claw-Wheel transformable hybrid robot, which can transform between the claw mode and the wheel mode for the investigation of various environment. The transformation process is done by simply folding or unfolding the front body through the active transformation mechanism. The claw mode driven by four unique claws is used to overcome rough terrain, especially steep stairs. The wheel mode driven by two driving wheels is used for moving on flat terrain without oscillations. For enhancing the stability during climbing steep stairs in the claw mode, we extend the body length to make the robot stride three steps. Compared with the robot designed for striding two steps, the COM projection of the robot will be assured to lie in the support polygon. Furthermore, the difference of the required torques between the front and rear motors could be narrowed down. In the wheel mode, the kinematics of specific differential drive is analyzed. The switching control strategy between the angle-tracking control and the speed control is employed to form complete wheels and follow a specified path. The claws in stance could drive the robot on the desired path by following the respective velocities differentially. To form the driving wheels, the claws in flight track the claws in stance in 90° phase difference by the angle-tracking control. The switching control strategy with yaw feedback make the robot track the desired orientation more correctly. The results from simulations and experiments are presented and discussed.