Although the story is stated by its creator to be An Aesop against being complacent with the inevitability of death, some readers have taken away that the story is against complacency with some other accepted part of life — capitalism, cancer, society, etc. — and the dragon's consumption of humans is meant to be metaphorical not for the lives claimed by mortality, but some other issue caused by the accepted part of life.
From the dragon's perspective, the story could easily turn into an allegory about resource conservation. The dragon cleverly uses humans as self-renewing livestock instead of quickly gobbling them up, which would leave it with no food.
Alternative Character Interpretation: Are the king's advisors convinced that the dragon is natural and inevitable when they fervently defend it, or are they just Too Dumb to Live and value the dragon for power over the masses over self-preservation, as they will also die to feed it one day?
Angst Dissonance: The king's advisors In-Universe towards the little boy who called out their pro-dragon rhetoric with a burst of emotion.
Angst? What Angst?: Before the little boy shook them in the hearing with his innocent cries, people quickly accepted their loved ones dying with barely anything beyond periodic mourning.
Anvilicious: The fable goes out of its way to defy and deconstruct Who Wants to Live Forever? supremely harshly to raise awareness and declares many vastly popular works incorrect. The Grim Reaper represents The Plague in its deadliest form and an Eldritch Abomination of an unprecedented scale that holds humanity in Stockholm Syndrome. Bostrom treats promoters of accepting death as conspiracy theorists that skew priorities and hide their errors with hollow rhetoric. In the appendix, Bostrom declares stories promoting accepting death as outdated and dangerous with one sentence, meaning he had to be heavy-handed in his situation to raise awareness.
Badass Decay: The entire society In-Universe, collectively, over the centuries towards resisting the dragon, before researchers turned back the tide.
Catharsis Factor: For centuries In-Universe, the horrors of the dragon forced people to cope with death increasingly extravagantly. The average citizens mostly tried to block out thoughts of their impending demise; girls commonly got pregnant by sixteen and spawned a dozen children to grow the population despite the steady deaths to feed the dragon. Spiritual and religious men placated the masses by saying that the sacrifices to appease the dragon gave life meaning and helped curb population growth while promising an afterlife to uplift them.
Consolation Award: Most of Bostrom's other works concerning superintelligence and doomsday are well-known and controversial, but this fable, while not talked about much in academia, was the first work of his to receive high-end attention on YouTube when the well-spoken CGP Grey animated it to advocate for life extension.
Glurge: This feeling is near requisite for readers of this fable, as the plot tackles the topic associated with some highly existential dread that is oblivion. It's guaranteed to be somewhat dark despite its uplifting message that we can conquer death despite the things our elders said.
Hard-to-Adapt Work: Some tried to animate the fable before CGP Grey successfully averted this fate. The previous videos contained unattractive graphics and a word-for-word reading, which is not particularly appealing. That Grey was already a certified gold play button holder certainly helped.
Nausea Fuel: The graphic animation of the dragon's revolting slimy green saliva and the chewed-up humans in the CGP Grey video count.
One-Scene Wonder: The sage who first suggested that technology could one day slay the dragon back in medieval times, credited for inventing "dragon-bashing literature," appears for two paragraphs.
Padding: Much of the original fable's details can seem like this trope in contrast to the CGP Grey animated version, including a tiger and rattlesnake hunt and an inquiry from the scientists about the missile's exact date of launch, meant as secondary Aesops.
Values Resonance: A literal example In-Universe: Over time, and with help from a crying kid, the anti-dragon sentiment of several scientists engraves itself into the public consciousness.
Visual Effects of Awesome: CGP Grey's animated version qualifies relatively to his other videos; though animated, they appear like a slideshow when played. While only barely showing characters moving, the video's graphics are excellent for someone who admits he "can't draw."
They Wasted a Perfectly Good Plot: Some detractors of the fable claim that it fails to touch on the wider social implications of immortality in favor of just bashing the ethical side as hard as possible. This position has itself garnered some criticism, as fans respond that the fable is not meant to address anything beyond the ethical side and that you don't need to know how to do something better than someone to know they're doing it wrong.
The Woobie: Implied In-Universe concerning the little boy that first called out the evils of the dragon, as well as when he was grown up and volunteering as a life insurance clerk. He became the epitome of the anti-dragon movement's talking points from his innocent outburst, and the king feels sorry for him enough to grant him a permanent place on his court once the kingdom finally slays the dragon.