I think people misunderstand what actually saved Aang and Appa for 100 years.
The Avatar State protected Aang, but Appa survived because he was trapped in the exact same iceberg with him the entire time. They were basically frozen together the whole time.
Aang didn’t just freeze himself, he froze the whole air bubble around them too, including Appa. So Appa wasn’t casually living for 100 extra years he was literally stuck in ice until they woke up.
And honestly it makes sense too because if Appa died in that iceberg, Aang probably would’ve died too. Their bond was way deeper than just owner and pet. The Avatar State most likely kept BOTH of them alive in there.
The REAL unanswered question is how momo was alive??😭
I have a question 🙋
We all know Aang only survived in the ice berg because he was in the Avatar state right? How then did Appa survive that long too?