Despite a common misconception, the grey tabby cat is not a breed of cat, but a color and pattern of cat.
In fact, the tabby pattern, which consists of stripes, lines, spots, or swirl patterns in the fur, is quite common in a number of different feline breeds.
The size and overall appearance of your grey tabby cat, aside from his coat color and pattern, can vary quite a bit depending on the breed. Still, when specifically talking about a grey tabby cat, we can conclude that his coat will be grey in color. Also, as we mentioned above, the tabby pattern can consist of stripes, swirls, spots, lines. Most distinctively, a tabby will usually have a pattern in the shape of an M on his forehead between his eyes.