1) youth who masterbaits so violently that he shakes the building
2) gay slang for a well built (gay) adolescent. Presumably a jock.
1) Max was such a thunder-chicken that I just had to leave the dorm room until he was done jerking off. It just wasn't safe on the top bunk.
2) Tom's years as a gym rat paid off. He's 17 now and such a thunder-chicken that he has all the old queens fawning over him.