After you get to the Dragon, pull out a decent bow or a slingshot and start pelting it. When you see blood, you'll want to start using your fists, since he takes extra torpor from them and won't hurt his armor. When he's out, quickly put some narcoberries (50?), or, if you can spare it, about 6 narcotics in his inventory along with about 15 raw fish meat. Feed him all the narcos at about half torpor, and boom.
You have a dragon.