Seen a few raid pets, like the Ji-Kun one, but with a starting price at 20k it didn't feel worthwhile to monitor it.
From what I've seen, checking it several times a week, it's mostly the argent tournie pets listed there, and those tend to sell for just over 1k, which isn't too bad a deal.
Also seen pets like the black tabby cat and the firefly sell for less than 4k, and I guess the other world drops can be found there as well but must be on rare occasions as I didn't see any yet and check it quite often.
There's also a bag full of darkmoon tokens listed occasionally.
Bring your own mailbox as there isn't any around and it will come in handy if you go on a bidding war when there's little time left of the auction.