Mucopolysaccharide is considered as the common active ingredient of animal drugs, such as skin (donkey-hide gelatin, sea cucumber, cicada slough, snake slough, etc. ), horns (horns, rhinoceros horns, velvet antler, etc. ), shells (concha Haliotidis, oysters, snails, etc. ) and scales (pangolin scales, tortoise plastron, tortoise shell, tortoise shell, etc. ).