It is but a figment of all you delusioned imaginations.
Please excuse me for displaying my ignorance but this is the conclusion of all my research. Of all the videos i watched in the media section of 'underflips', not a single video looked the same. So my conclusion is that nobody actually knows what an underflip is, therefore, it does not exist.
I know that i will get flamed for this, but just remember that i hate all of you just as much as you hate me.
Yea I want cheezy poofs