<P> The platypus has been featured in the Dreamtime stories of indigenous Australians, who believed the animal was a hybrid of a duck and a water rat . According to one story, the major animal groups, the land animals, water animals and birds, all competed for the platypus to join their respective groups, but the platypus ultimately decided to not join any of them, feeling that he did not need to be part of a group to be special . </P> <P> The platypus has been used several times as a mascot: "Syd" the platypus was one of the three mascots chosen for the Sydney 2000 Olympics along with an echidna and a kookaburra, "Expo Oz" the platypus was the mascot for World Expo 88, which was held in Brisbane in 1988, and Hexley the platypus is the mascot for Apple Computer's BSD - based Darwin operating system, Mac OS X . </P> <P> The platypus has also been featured in songs, such as Green Day's "Platypus (I Hate You)" and Mr. Bungle's "Platypus". It is the subject of a children's poem by Banjo Paterson . </P> <P> The platypus has frequently appeared in Australian postage stamps and coins . The earliest appearance is the 9d Australian stamp from 1937 . The platypus re-appeared in the 1960--64 Australian Native Animal Series . Souvenir sheet of "from" Laos and Equatorial Guinea has also featured the animal . The platypus has appeared on a 1987 36 cent stamp and an Australian 1996 95 cent stamp . The 2006 Australian Bush Babies stamp series features a $4.65 AUD stamp of a young platypus . A 5 cent stamp also produced in 2006 features the platypus also . Since the introduction of decimal currency to Australia in 1966, the embossed image of a platypus, designed and sculpted by Stuart Devlin, has appeared on the reverse (tails) side of the 20 - cent coin . </P>

Why is the platypus in the kingdom animalia