There are still plenty of villainous dragons flying around in fiction today, from the three-headed King Ghidorah to Marvel’s Fin Fang Foom. However, in the past few decades, popular culture has reevaluated the old “evil dragon” concept and come to prefer more sympathetic — or even heroic — portrayals.
Some examples? Try Falkor, the fluffy white “Luck Dragon” in The NeverEnding Story. More recently, there are the Inheritance Cycle books, which view dragons quite positively. Other popular movie dragons have included Toothless from the How to Train Your Dragon movies, the lovey-dovey dragon in Shrek (a direct refutation of the evil dragon trope), Mushu in Mulan, and the toruks in Avatar. Most famous of all, of course, are those three unforgettable dragons Daenerys Targaryen commands in her quest to overtake the Iron Throne. Yeah, you certainly wouldn’t want to mess with Drogon, Viserion, and Rhaegal, but they’re largely portrayed as loving creatures that simply want to protect their mother. Any aggressive actions they do take, over the course of the series, can usually be chalked up to human direction rather than stemming from some “evil” nature.
So a century ago, an adventurous kid would dream of slaying an evil dragon. Today, most kids would probably rather ride a dragon instead, and maybe enlist that dragon’s help in burning up bad guys.