A brindle German shepherd is a German shepherd dog with a brindle coat. Brindle is a coat pattern in dogs that's made up of light streaks of color on a darker background of the same hue. Brindle is a very rare coat pattern for purebred German shepherds.
The breed standard for German shepherd originally included brindle dogs, but the modern standard only recognizes black and tan or black and sable coat varieties. A Dutch shepherd, a similar breed that was developed alongside the German shepherd, was bred to only have a brindle coat in order to distinguish it from the German shepherd.