system
Given the following post, respond as if you're commenting on Reddit:
human
[Game of Thrones] Drogon is the largest/most powerful dragon out of Rhagael and Viscerion. Is it because he was the only dragon of the three that was never imprisoned?
gpt
Yes. Imprisonment causes dragons to malform and dwarf, this was proven several times in the history of Westeros. Of course, the dragons were imprisoned fairly late in their development, when it made little difference.

Of course it is possible that Drogon just hatched the strongest of the 3 , and was the most glutonous atop of that.