The non-helicopter rated pilot reported that he had departed from a stationary trailer and hover taxied in ground effect. Upon reaching a taxiway that was parallel to the runway, he lost control of the helicopter and it impacted the ground multiple times before coming to rest on its side. A post-crash fire ensued and the helicopter was destroyed. The pilot stated that he believed he lost control of the helicopter and it had been “running fine” before the accident. Witnesses stated they observed the helicopter lift off from the transport trailer and that once the helicopter cleared the trailer, “it got real wobbly.” The main rotor blades struck the ground two or three times and while continuing forward, the right landing gear skid tube “hit the ground pretty hard”. They said, “the helicopter then bounced back into the air, spun to the right (clockwise) and landed on its left side.”