A/N: Because he is, in fact, important to the story, we need to consider an unusual point of view.
Disclaimer: Okay, I don't own Avatar or its characters. Owell. I'll get over it. So will you. In the meantime…
CHAPTER 3:
His allegiance was, of course, to Aang. But he couldn't help but love the Water Tribe boy who, for all his complaints, still found the time to comb his fur for parasites, brought him treats of prime fruit – even out of season, if he could find them – and talked to him as if he might possibly believe Appa understood him. Which, of course, he did.
When Aang and Sokka had approached Appa about leaving Aang behind for an excursion beyond the mountains to the coast for a few days with just the Water Tribe boy and girl, and long days without even them for company, neither was sure Appa would acquiesce. But Appa had certainly noticed how unique he was now in the world, and vaguely understood that this was the result of some unnatural process. A process they were fighting, and it was only right he should assist in whatever way he could.
It didn't hurt that he simply liked Sokka, and Aang's adoration of Katara had not gone unnoticed by the great beast, either.
So he flew the pair to the banks of a river between cities on the northern Earth Kingdom shore.
He waited patiently for a call from the whistle the girl now wore on her neck, while being fed by quiet men in green who could raise an earthen barrier to shield him from view at a moment's notice. Of course, there was only a reasonable limit to his patience in such a wait.
After all, he was no longer encased in an ice-berg.