Hippaul Racing is a mini-game that can be played at the beginning of Disc 3 in Alexandria. As soon as you leave this area and continue with the plot of the game you will never get the option to play it again.
Travel back to the entrance to Alexandria (where you first start the game with Vivi). Speak to Hippolady on the left side of the screen and, when asked if you would mind racing against Hippaul, select “I don’t mind”. This mini-game has a key item called the “Athlete Queen” and this is the only way to obtain it. You will have to continue to attempt to beat Hippaul until you defeat him at level 80 to obtain the Athlete Queen.
The game is easy enough - just hit the two buttons (Square and Circle) alternating as fast as possible. You can cheat at this mini-game if you have a turbo-style controller but other than that there is not much that you can do to make it easier. You can customize the controller if you’d like to two buttons that are easier to hit (such as L1 and R1). The rewards are not that great so don’t worry if you can’t do it.
The rewards include:
Level 10 - Wyerd Card
Level 20 - Carrion Worm Card
Level 30 - Tantarian Card
Level 40 - Armstrong Card
Level 50 - Ribbon Card
Level 60 - Nova Dragon Card
Level 70 - Genji Card
Level 80 - Athlete Queen (Key Item)