A passively transformable wheel includes a wheel base including a centrally positioned transmitter rotation shaft and one or more passive leg rotation shafts positioned in the outer periphery; a force transmitter rotatably coupled to an end of the transmitter rotation shaft, the force transmitter including a trigger slide and one or more passive leg joints spaced apart from one another; a trigger leg arranged between the wheel base and the force transmitter and rotatably coupled to the trigger leg rotation shaft, the trigger leg including a trigger joint fitted to the trigger slide; and one or more passive legs arranged between the wheel base and the force transmitter so as not to interfere with the trigger leg and rotatably coupled to the passive leg rotation shafts, the passive legs including one or more passive leg slides engaging with the passive leg joints of the force transmitter.