"There's no need." Aaron spoke calmly. "How long do you think you can hide that dragon's identity?
Given how fast dragons grow, in less than two weeks it'll be several times its current size. After a month, this hut of yours probably won't even be able to hold it.
By then, will you still be able to keep it under control like you do now?
Even if you can, one careless sneeze from it could probably burn this wooden hut to the ground. Then everyone at Hogwarts will know that the gamekeeper is raising a dragon."
"I know I can't keep raising it forever," Hagrid said dejectedly. "But I can't bear to just abandon it like this. I can't do that."
"That's your problem. It has nothing to do with me.
Using the Fidelius Charm on a secret you're destined not to keep is completely unnecessary."
"Abei!" Harry looked at Aaron. "It's a magical creature too, right?
It was this size at the start of term, and it's still this size now. It's barely changed at all.
But when Abei fought, it grew much bigger, and now it's turned back to normal again."
"What are you trying to say?"
Hagrid seemed to realize something, and a glimmer of hope appeared in his eyes. He pleaded, "You must have some way to let magical creatures control their body shape. Could you arrange something for Norbert—this Norwegian Ridgeback—as well?"
"Heh! You really do have vivid imaginations.
Abei is a magical creature. If I remember correctly, there are magical creatures that can control their own size, aren't there?
There aren't many, but the books in the Restricted Section do mention one or two such creatures. To give a simple example, werewolves transform on nights of the full moon.
And I don't understand where