Saeviomagy
Adventurer
Seriously, though, this thread is making me think that the best and most sensible way to make dragons "deserve" their reputation is for them to proactively seek out threats (PCs) and deal with them on their own terms... preferably long before the party's average level catches up to the dragon's CR.
http://www.pvponline.com/comic/2015/01/01/accrual-mistress
I think that's much more likely.
Seriously though - the truly canny and adventurer-aware dragon probably coexists with it's neighbours to some extent. If it's just smashing it's neighbours and carrying off their cattle, it's already exhibiting an amazing level of hubris and a great lack of foresight, and it won't be long before someone shows up and defeats it.