When the Crazy for Cats achievement was discovered on the PTR, the first thing players asked for was a title to go along with it. Namely, something to do with being a Crazy Cat Person. Good news! We got what we asked for: The Crazy Cat Lady and the Crazy Cat Man were both added as titles in the latest patch 5.4 PTR build.
Keep in mind that you need 20 out of the 24 cats listed under the achievement. Overall, the achievement doesn't seem too difficult for a battle pet collector to earn, especially since one-third of the cats on the list are purchasable via NPCs. A few felines on the list are harder to come by, including the Nightsaber Cub and Spectral Tiger Cub from the TCG, and the Spectral Cub awarded to players participating in the Shanghai 2012 Battle.net World Championship.
I'm crossing my fingers for the title off the bat when the patch drops!