What is true of the dragon is that it will die just as all the dragons before it; that once fierce and formidable, it will lose any and all of those who could be--and perhaps once were--friends (if it ever had a friend). The dragon dies in more than the physical, but of a broken heart, shattered by its deep insecurities and insistence on taking it all, everyone and everything. Yes, the dragon is insatiable and thus does not have a means or method to give or even express gratitude.
Who or what is the dragon?
"Good-reads", a Website of quotations, offers much on the beast or behemoth, whether words of tribute or terror; but the dragon is finally and fully unto itself; one with whom the figurative world will fight, fear and not forget. The dragon is does not have to look the part, as with the illustration above, but nevertheless be the part.
From C.S. Lewis, The Voyage of the Dawn Treader,
Sleeping on a dragon's hoard with greedy, dragon thoughts in his heart, he became a dragon.When and where one consorts with dragon(s), so too will they become one, of the same mind of madness, a masochistic, their heart diseased with death and destruction. Dragons cannot love or otherwise are incapable of care, caring, except to the extent that it serves them for the moment. They (it) may appear to at first give a care--and even speak on it--but they always and forever default to death and destruction--devoid of the capacity for care, caring and compassion. The dragon considers love as a fault, a weakness.
Beware of the dragon's breath that breathes your last.