Baseless Dragon Biology Theory · 8:54pm Jun 27th, 2014
Theory: Dragon growth is tied to their fire.
It's clearly not tied to age, diet, or simple hormones. Or, for that matter, simple physics. Evidence for this claim:
* Spike's growth spurt into his teen form and Godzilla form. It happened far too quickly, and where did all that mass come from?
* Spike's shrinking back to his old size. Where did the mass GO?!
* Spike has not appeared to grow at all in the last four years.
Proposed answer: magic (duh)
Hypothetical Life Cycle for Dragons:
Newly hatched dragons wouldn't be expected to use their fire at all; their parents would be there to protect and care for them. This would allow the hatchling to conserve their fire and focus on growth.
At a certain size, a young drake would leave the nest and strike out on their own; of moderate size and with no hoard to their name, they still wouldn't be using their fire very much. Claws, fangs and tails would be sufficient for most fights; and with no treasure to steal, very few beings would pick a fight in the first place. Experimentation and competitive displays of their fire with other drakes begin at this age. As they practice and show off their flame-skills, the drake's growth will slow. (the conflict between needing flame for growth and displaying it as a sign of maturity is not accidental; a big flame declares "I have so much fire, look how much I can waste")
As a dragon grows larger and acquires a more valuable hoard, it becomes harder for the dragon to rely on its body to defend the hoard. Smaller creatures can hide in nooks and crannies, dodge with frustrating speed, or even try to shield themselves with the treasure they came to pilfer. Thus, older and larger dragons use their fire more often; it can cover large areas and get around most defenses, can be directed as easily as looking at the target, and most dragons prefer to hoard flame-resistant gems & gold. This increase in fire-use leads to a plateauing of their growth; any growth they experience at this size is negligible enough to escape notice.
Ramifications for Spike:
As long as Spike is with Twilight and Celestia, his growth will be stunted.
Unlike other dragons his age/size, Spike is using his fire constantly. In the first episode, while still in Canterlot, Twilight has him send a message to Celestia about Nightmare Moon; the casualness with which this is done implies that it's a common practice for them, and has been for quite some time. After moving to Ponyville, he's still used to correspond with the Princess at least once a week.
If Spike were allowed to bank his fire for a month, a season... he'd experience another growth spurt, but without the obsessive side-effects of the greed induced one.
What's Up With the Greed, Anyway?
We've already established that dragon growth isn't tied to anything physically real; see "mass from nowhere." I propose that greed is equivalent to a hormone for a dragon. Much like a hormonal imbalance in less magical creatures, too much of certain emotions can drastically alter a dragon, physically and mentally.
In the wild, or around other dragons, greed is actually fairly self-regulating. There are either larger dragons around to knock some sense into the greedy one, or they reach a balance of greed & cunning as they are unable to protect their hoard if they're easily outwitted. Spike was only such a problem because he was in a settlement totally unprepared for dealing with a dragon.
