Having just realized that I can't get a pet with arena tickets unless I earn a PvP rank, I decided to give arena another try. I'm finding it very frustrating. I've spent 2 hours queueing for matches, but with 4 wins and 4 losses, my rank hasn't gone up at all. The people who beat me seemed to have an endless supply of treasure cards. I realize treasure cards are fair in the sense that I could go buy a hundred tower shields, stuns, and steal charms also, but to be honest I'd rather not.
Update: I still don't like Arena BUT it looks like you don't need to have an Arena title to get the reward pets. Yay!