The Oxymoron is a twisted experiment in disc design. It is a square-shaped "disc" that is not PDGA approved because it is not the right shape for competitive disc golf. But that didn't stop Doomsday Discs from making them for entertainment purposes and casual rounds. It has a round inside rim on the bottom so that it feels more natural when gripped...well...as natural as you can get with a square disc. The square edges tend to give the "disc" extra helicopter-like lift as it spins in flight, making the disc rise as it flies.
