The Schildkröte, literally meaning "turtle", was powered by a 70 hp, air-cooled Tatra V-8 petrol engine. Armor protection on the Schildkröte varied according to each prototype model, the Schildkröte I having 7 mm to 7.5 mm armor plate and the Schildkröte II and III models having a maximum of 10 mm of armor plate. The Schildkröte I prototype was armed with a dorsal 7.92 mm MG 81Z machine gun, the Schildkröte II having far more varied armament of either a 20 mm MG 151/20 or a 7.92 mm MG 81Z and a coaxial 7.92 mm MG 34. The Schildkröte III had probably the most standardized armament of the three, that being a single 20 mm MG 151/20 automatic cannon. The Schildkröte design measured 5.18 meters long and 1.90 meters wide, and weighed 5,000 kilograms. The Schildkröte was also capable of amphibious travel.
While the Schildkröte I, II and III may be considered variants, they were merely improved versions of the earlier prototype. The main variant of the Schildkröte design would have been the Einheits Panzerspähwagen Trippel E3. The E3 featured a more powerful 125 hp, air-cooled Tatra V-8 petrol engine and armor protection ranging from 5.5 mm to 14.5 mm of plate. A variant of the E3 itself also existed, this being the E3M, which was a prototype ammunition carrier that featured no dorsal turret. The E3 was the only prototype variant of the Schildkröte series produced.
The Schildkröte was designed in 1941 by Hans Trippel for the German Wehrmacht to be used as a standard armored car Three prototypes, based on the S.G.6 vehicle, were completed by Trippelwerke at Molsheim in October 1942, and sent for military testing. However, Trippel's designs were unable compete with the current German armored cars of the time. Various problems dogged the project, such as the overall light construction of the chassis, making the Schildkröte unable to carry heavier armor and armament, as well as problems in acquiring sufficient materials for full-scale production. By the end of 1942 the entire project was cancelled. In 1943-44, Trippel once again attempted to design an armored car suitable for military use, resulting in the Einheits Panzerspähwagen Trippel E3, based on the Schildkröte III. This too failed, and in the October of 1944, Waffenamt concluded that such a vehicle was unnecessary.