Purrloin is a basic Pokemon that was introduced in the generation v games, Pokemon Black and White. It is a dark pokemon that is obtainable in the wild on routes 2, 3, and the Dreamyard. In Black2/White2 it is available on routes 3, 19, and 20. They are fairly common Pokemon with low defense, but their speciality is in their speed. Being a dark type, they are immune to Psychic and resist Ghost and other Dark attacks. However, they are weak to Fighting, Bug, and the new Fairy types. At level 20 it will evolve into Liepard.
Purrloin is a purple cat with white patches, so it may be somewhat difficult to see that it is actually based on a black cat. In many superstitions, the black cat is considered bad luck, and in the Pokemon world, a Purrloin may cause something you treasure to go missing, they are known to steal after all.
Purrloin's English name is a combination of "purr" and "purloin", or simply a corruption of the word purloin. In Japanese, Choroneko may come from "choromakasu" (to pilfer) and the Japanese word for cat, neko. Many of Purrloin's translations carry the same theme: the combination of cat with a word that means "to steal".
There is a subtlety in Purrloin's design with its pointed (horn-like) ears and its pointed tail. Since Purrloin is a dark type and based on black cats, there is a possibility that its design could also mimic that of a demon cat.
Purrloin's design carries over to its evolved form, Liepard, which is a leopard with stereotypical thief features.
I have a tendency to be attracted to Pokemon that have really terrible base stats but very adorable designs. This is one reason I really love Purrloin and was very excited about the reveal. I think Purrloin, and its evolution, are both very solid designs in the fifth generation games. I also was excited to have a cat Pokemon that was not a normal type! It was a nice addition to be able to have a cute Pokemon with a strong type. Purrloin may be weak, since you do catch them early on in the games (they cannot be too overpowering), but with enough training and vitamins (I am all about them) you can have a strong addition to your team. All in all, I'm just shallow and love cat Pokemon.