Which of these is a common horse breed?

Castra, it literally says it's a very common horse breed...

The description implies that the thoroughbred is not a common breed of horse. There are many rare breeds of horse, but the thoroughbred is not one of them. Vertually every racehorse on the planet is a thoroughbred. Also.. Tabby is not a breed of cat. It's a colour-way, a mixture of stripes and spots of various colours.

I wonder what a tabby horse would look like. And would a beagle horse have long, the floppy ears ? And the poodle horse would have to go to the groomers to look fabulous.