A transformable toy (100) which is instantaneously changeable from a flat plate-like shape to the shape of a character figure and which is used to play a game by rotating a roulette wheel (189) to compete for the score of attack or defense. A transformable toy comprises character-figure constituting members (111, 122, 131, 141) foldable to a state of a generally flat plate and rotatably connected to each other, elastic members each providing between each of the character-figure constituting members, a roulette wheel (108) attached to any of the character-figure constituting members, a rotation imparting mechanism for imparting rotation to the roulette wheel, and an engaging means (157) for maintaining and releasing the folded state of the character-figure constituting members. When the character-figure constituting members are folded against the elastic forces of the elastic members to operate an engaging member, the character-figure constituting members are rotated and caused to protrude. This makes the outline of a character figure protrude and appear and, at the same time, makes the roulette wheel to rotate.