Dragon's are cool, and they are not mythical. Although they have been exaggerated.
They are more similar to Gargoyles. They can't fly, they glide and they don't breath fire, but spits acid that burns if ignited.
Dragon slaying was done when the Dragon had glided as far as it could, and ran out of acid to spit.
Their weakness came when the world became to populated for them to have a place safely glide to before climbing to higher ground.
Their claws were built for climbing near vertical rock faces to escape any danger, making their nests on unreachable peaks.