[b]AS7-D Atlas[/b]

The Atlas is probably the best-known BattleMech to ever set foot on the modern battlefield. Designed with specifications from Aleksandr Kerensky himself in 2755 in the midst of the Cameron Edicts, the Atlas was originally intended to ensure SLDF superiority over the Star League member states. Though the inexorable arming of the Great Houses continued, the Atlas proved itself to be everything General Kerensky requested. With the largest amount of armor of nearly any 'Mech, crippling firepower, and the foreboding skull-shaped "Death's Head" cockpit/head assembly, the Atlas lived up to its reputation.

(From https://www.sarna.net/wiki/Atlas_(BattleMech)
atlas (battletech)