Karl-Gerät' (040/041) (German literally 'Karl-device'), also known as Thor and Mörser Karl, was a World War II German self-propelled siege mortar (Mörser) designed and built by Rheinmetall. It was the largest self-propelled weapon to see service. Its heaviest munition was a 60 cm (24 in) diameter, 2,170 kg (4,780 lb) shell, and the range for its lightest shell of 1,250 kg (2,760 lb) was just over 10 km (6.2 mi). Each gun had to be accompanied by a crane, a heavy transport trailer, and several modified tanks to carry shells.
Here is the low poly model of Karl Tank... Modeled on 3ds max 2012. ready to render on max with vray 2.0.