A heavy self-propelled gun based on IS-2 tank chassis. A successor to very similar SU-152 gun. Fired various shells weighing from 40 to 56 kilograms, able to crack open even the most heavily armoured German tanks. Nicknamed "Zveroboy" (The Beast Killer), because its most frequent opponents (aside from strongholds) were named after wild animals (Tiger, Panther, Elefant etc.)