Henry sees the new attack as "an onslaught of redoubtable dragons." what does he do and why?

The youth felt scared and paralyzed with fear. He feels numb and is convinced that his foes are machines of steel, 

He became like the man who lost his legs at the approach of the red and green monster. He waited in a sort of a horrified, listening attitude. He seemed to shut his eyes and wait to be gobbled.