I've run across references to the DDR German Shepherds and in my research I've heard they're a strain of the GSD originally bred by the East German military and police forces prior to Germany's reunification. From what I've heard they've got higher drive, tend to be towards the bulkier end of the breed according to the Riddlebrook German Shepherd's website:
What are some other differences between the DDR lines and American and Western German lines?The Breeding Criteria As Well As The Harshness Of Their Environment Shaped The Look Of The East German DDR Shepherd Into One Of Pure Intimidation. They Had Large Heads, Broad Shoulders, Deep Chests And Dark Coats. They Were Truly An Fearsome Looking Shepherd -- The DDR Shepherd Was A Sight To Behold.