Ichthyophis is a limbless amphibian of 15−22cm length that lives in burrows in moist soil. Reptilia comprises amniotic tetrapods with dry skin having epidermal scales and incompletely four chambered heart. Aves are warm blooded tetrapods in which the forelimbs are modified into wings. The body is covered by feathers and the jaws are modified into horny beaks. Mammalia is a group of most advanced chordates which are homoiothermal hairy tetrapods having mammary glands, in the female.