Agar gels with hierarchical rough surfaces, referred to as "fractal agar gels," were prepared to model biological surfaces coated with mucus. Agar gels with rough surfaces of fractal dimension D = 2.2 were synthesized by transferring a fractal surface structure of alkylketene dimer (AKD). The rough structure accelerated the spreading of water droplets and induced the appearance of a wicking front. The mechanism of acceleration of the spreading on fractal surfaces based on a semiquantitative theoretical model was also clarified.