Been playing a long time, and I have a decent amount of achievement points (18,420), but this Stunted Direhorn is probably the one thing I am most happy to have done.
I just got it, making it my 600th pet. 2 pets left that I can get, but both are seasonal (arena, guardling) and I missed the Ony Whelp (GRRRRRRRRRR) and I sold my Murky from the first Blizzcon (DOUBLE GRRR). I don't count those two since one is simply not possible (I have ticketed many times) and I am not crazy enough to spend $2k on a pet.
So, just working on the pet levels now, and wanted to celebrate this little guy. I sure did hate earning him.