A long-dated term. It is of Greek origin when Greek wrestlers took young boys as their prizes after wrestling matches. Usually these body builders would have rough, usually painful, anal intercourse with young chubby boys all night. The young boys were usually rewarded with front row seats to the wrestler's next match as a reward. These men were so massive that they are compared to the Hulk (whom also happens to be green). Hence the Green Thunder.
That boy is going to receive the Green Thunder tonight. He should get a WHOLE ROW of front row tickets.