The Maus was one of those lunatic German obsessions with gargantuism that bedevilled their war effort.
Only two hulls for this 188 tonnes superheavy tank were built before the factory was overrun by the T34s of the Red Army. It had a 128mm main gun and a 75mm as secondary armament.
The Maus made no sense at all either as a battle tank for real or on the wargaming table but, you know, I am going to buy one anyway.
Just gotta be done.