The first Olympic mascot 'Waldi' a Daschund dog appeared at the 1972 Munich Olympic Games. Mascots are used to communicate the Olympic spirit to the general public, especially youth and children. They are usually a character or animal native to the country where the games are being held and showcase the history and culture unique to the host city. In more recent years it has been common to have more than one mascot. This could be to ensure gender equity but has undoubtedly increased the merchandising potential of the Olympic mascot.

The Sydney Olympic Games 2000 had three mascots of which Millie the Echidna (spiny anteater) was one, the other two were Olly the Kookaburra and Syd the Platypus. They were designed by Matthew Hattan and their purpose was clearly outlined by the Sydney Organising Committee of the Olympic Games (SOCOG). It stated 'Syd, Millie and Olly's role [was] to communicate the ideals of the Sydney 2000 Olympic Games… Their mission [was] to inspire, entertain, inform and embrace'. The mascots were commercialised in a range of products, toys and the partnership with McDonalds.

Together, Syd, Olly and Millie represent earth, air and water. Olly, the Kookaburra epitomises the Olympic spirit of generosity, Millie an echidna is a techno-whiz and Syd the Platypus reflects the environment and captures the vigour and energy of Australia and its people.