Personally I’d recommend you get the Kirin Tor Familiar, there are other pets that I think are worth your time but I think that one is pretty unique. I made a post saying where to get pretty much all the pets in WoW…
I can’t quote the Kirin Tor Familiar part in my post regarding the pet as the post is locked.
Actually I found a way… I can quote it from this post.
Kirin Tor Familiar
This pet is obtained from the achievement Higher Learning, the achievement has you go around Dalaran clicking on specific books, these books spawn in specific locations and despawn once read I believe.
The book locations are...
[The Schools of Arcane Magic – Abjuration]
Location: Dalaran Visitor Center (52.2,55.5), on the floor to the right as you go in, in front of the little table with books on it
[The Schools of Arcane Magic – Conjuration]
Location: Violet Citadel (30.9,46.3), group of bookcases on the right as you go in, Bottom of the left bookcase.
[The Schools of Arcane Magic – Divination]
Location: Violet Citadel (26.5,51.7), Up the stairs to the left, on the floor in front of the bookcase, next to the sands of time portal.
[The Schools of Arcane Magic – Enchantment]
Location: Threads of Fate (Cloth Armor shop)(43.6,47.1), Go up stairs out on the balcony on top of a crate to your right as you walk out onto the balcony.
[The Schools of Arcane Magic – Illusion]
Location: Violet Hold (64.5,52.8), as you go in head to the left and against the wall on the left crate, next to Archmage Timear.
[The Schools of Arcane Magic – Introduction]
Location: Violet Gate (Crystal Portal)(56.7,46.1), to your right as you enter (northern bookcase) on the floor in front of the bookcase.
[The Schools of Arcane Magic – Necromancy]
Location: Legerdemain Lounge (46.9,39.1), Upstairs west room, empty bookcase
[The Schools of Arcane Magic – Transmutation]
Location: Legerdemain Lounge (46.9,39.8), 1st floor western bookcase near the door.
You could also go for the Fawn but you’d need 75 pets for that.