The kneazle can be quite the feisty creature. They can be very aggressive, especially toward wizards who make a bad impression on them. Most kneazles make excellent pets, but like a wand, the kneazle chooses it's owner. So only some wizards can own them. For example the well known friend of the famous Harry Potter, Hermione Granger, I'm sure you all know about her. Anyway in case you didn't know, she has a pet cat called Crookshanks. Crookshanks is half kneazle, that explains why he is so angsty. Here is a picture of Crookshanks, the half-kneazle. 

Kneazles have an outstanding sense of direction, if lost, they can guide their owner home avoiding all danger. They also have an uncanny ability to detect whether or not a person is trustworthy or suspicious. They react badly to those deemed distrustful.