Where do I find them other than Trollsblight Cavern? I'm rather low level so I haven't unlocked all the areas, but I'm curious if they appear anywhere else and if I can find rare/Epic/legendary versions of them rather than only common/uncommon? Is this also the reason gened sylvorpas are rare?

@Frency,
That's a really good question. I know 100% that they appear in the 3rd area in Astryl's Tranquility. I'm not sure about elsewhere.

I'd be curious if they appear as a possible pet to capture in town raids, if anyone else knows the answer to that? Since town raids have a very high chance of giving rare+ pets.

I can't remember where they appear, but I do believe I have seen them on raids before. Also, if I remember correctly, the first two regions will only give at most rare pets. Can't remember about the 3rd region.

I do know that most of the epic/legendary pets people encounter happens in the festival zone. I've personally not met any epic/legendary pets outside of that.