To get the blackness of the cat correctly it was important to shoot in [M]anual mode.
So just how do you know what manual settings to use?
Well, a really quick way of doing it is to shoot in [A]perture or automatic mode, review the shot and take notice of the shutter speed and aperture; if it’s too light – put your camera in Manual and put in the same settings but increase the shutter speed (or alternatively increase the aperture).
One of the most important parts of photography is composition, in this shot cropping it to a square worked quite well, with the cats face being in the intersection of an imaginary set of lines, this is called the “Rule of thirds”, where the point of interest is composed to be near the intersections. The gridlines in the viewfinder are a great tool to use if you want ti use the default image format of your camera (i.e. 3×2)