Answer
Flatground ollie is the first trick invented by Mullen. It is a skateboarding maneuver where the rider jumps into the air while the board remains on the ground, and then lands back on the board. Mullen invented this trick in the early 1980s, and it quickly became a staple of skateboarding. The flatground ollie is a fundamental trick that has paved the way for many other advanced skateboarding tricks.