To provide a water-discoloring toy capable of forming a sharp see-through image, and satisfying water resistance and folding-up resistant strength; and a toy set of setting the toy and a water-sticking means.

This water-discoloring toy 1 is constituted by forming a porous layer 3 of fixing a particulate-like silicic acid to a binder resin in a dispersion state, on a support 2 composed of a fabric web having basis weight falling within a range of 30g/m2-1,000g/m2. A water-discoloring toy set is also constituted by setting the toy 1 and the water-sticking means 6.