Most malformations of birds are classified either as genetic or unknown etiology or as nutritional and toxic etiology (2). The present paper records three rare monsters of domestic fowl. Four thousand two hundred and thirty-five dead-in-shell embryos of two strains of white leghorn (Pbl and Pb2) were examined for malformations from November 20, 1981, to April 28, 1982. Three rare monsters (four-legged and four-winged) were discovered. In one monster of strain Pbl due to hatch on January 29, 1982, the first two legs originated from the first thoracic vertebra and the rear legs originated from the center of preand post-acetabular parts of the ilium (normal place of origin of legs). The first pair of wings originated from the base of the first pair of legs (the base of last cervical vertebra), and the rear pair of wings originated from the base of the fifth thoracic vertebra. The upper beak was 1/3 the length of the lower beak. The other two monsters were found in Pb2-strain embryos due to hatch on January 19, 1982. In one of these, the upper beak was crossed to the right, but the upper and lower beaks were of equal size; the crossed beak was associated with microphthalmia (Fig. 1). In the other case, the beak and eyes were normal. The origins of the legs and wings in these two cases were the same as described in the first monster. These monsters of the domestic fowl are a rare phenomenon, as is apparent from the present study, in which three cases were recorded out of 4,235 dead-in-shell embryos examined (0.07%). No case of four-legged, four-winged monsters had previously been reported in the literature.