A female Rana kl. esculenta was crossed with three different R. lessonae males. Three froglets with unexpected phenotypes appeared. Two of them were chimerae with one side of the body of lessonae, and the other of escutenta phenotype, and one displayed lessonae, instead of the expected esculenta, phenotype. Blood of three individuals was composed of small haploid and large triploid erythrocytes. These results indicate that the froglets were 1n/3n mosaics.