Glen Bonin and his friends were tempting fate by pulling the animal by its tail off Prater Road in Louisiana.
They blinded the animal by throwing their shirts over its face.
The giant alligator then leapt up in anger, snapping its jaws shut on Bonin's hand, 'KPLC TV' reported.
Bonin was later hospitalised where he received 80 stitches on his hand.
"It felt like someone was pulling my arm out. I thought I was about to lose something. It felt like it lasted forever," Bonin said.