"no-neck dude"

Hey guys, this phrase goes way back. It comes from Tennessee Williams' Cat on a hot tin roof, whose date I dont quite remember but must be around 1940-1950. It was used as a memorable insult to describe Mae's awful children "no-neck monsters", meaning fat, overfed brats. I think TW invented the phrase, or picked it from his southern roots somewhere (he had a good ear for local dialogue).

In Die hard 3 there was scene when Zeus asked his nephews:

"Tony. That no-neck dude they call Bad T?"

the exact meaning of "no-neck" - ?