Petey the dog, or Pete the Pup, is "Millie" in this short.
The 'Olympic Games' of the title - and the ensuing all-out Our Gang battle - are played out in a field called 'Dooley's Flats' in the title cards. This field apparently is a then-empty lot in Culver CIty, California, near the Hal Roach Studios. A sign visible in many of the scenes advertises "Motor Ave. Business Frontage / Harry R. Leech", with an address and phone number for the seller in Santa Monica. Motor Avenue is just a few blocks West of the Hal Roach Studios location. Homes and other buildings can be seen at the edges of the field, as cars of the period (1920s) pass by on nearby streets.