They call the Super Bowl the greatest show on earth, but for one Australian filmmaker the battle between the NFL's elite will be the sideshow for a $US1 million ($1.4 million) contest between an unborn foetus, a pack of dogs and a serial Tinder date. Peter Carstairs is one of three finalists in the Doritos Super Bowl commercial competition, which will see the winner's 30-second ad aired during the Super Bowl 50 on Monday. The 45-year-old from Melbourne has some tough competition vying to win the decade-old crowd-sourced media campaign for their chance to 'Crash the Super Bowl', win a $US1 million cash prize and work with Hollywood blockbuster director Zack Snyder. His entry - which cost $US2000 ($2800) to make - was inspired by a trip to the hospital with his then-pregnant wife, actress Sibylla Budd. The ad features an unborn baby who can't get enough of Doritos chips during an ultrasound. Carstairs' creation is up against two ads from Los Angeles-based filmmakers. One, made by Jacob Chase, 29, follows a posse of resourceful dogs as they try to outsmart a grocery store manager The other, by David Rudy, 42, follows a Tinder-inspired string of awkward first dates.