I had a dream about vanity pet achievements last night lol. In the dream I was attempting to find a solution to some issue with newer players vs. older players and new collections vs. old collections.
The answer to it all? Using the Pet Journal to cage all your vanity pets and relearn them in a special companion "code" to unlock special achievements.
So in my dream, there was an STV "code" to unlock the pet achievements found there, and it was "bunny, tiger, tiger, tiger, bunny". (Because we have tigers as minipets right? ROFL!)
Anyway, you could either capture the pets in that order (if you didn't already have them) or you could use your Pet Journal to put them into cages and then relearn them in that specific order. Doing so would unlock something in the achievements, but now that I think about it... my dream never revealed what it was. Nor did I find out what specific issue this way of doing things was a solution for.
Despite none of this making sense now, it seemed to make perfect sense in the dream. I knew I was dreaming but it still felt like a "EUREKA!" moment while I was watching it all play out. Ah well. :P