Sturmtiger is the common name of a World War II German assault gun built on the Panzer VI Tiger I chassis and armed with a large naval mortar, the 38 cm SturmMörser RW61 L/5.4. Its primary task was to provide heavy fire support for infantry units fighting in urban areas. Only 18 were built in total, from battle-damaged Tiger tanks. The vehicle is also known under the names Tiger-Mörser, Sturmmörser Tiger and Sturmpanzer VI.