oh! That's right sir smithlabs, I was thinking of the Tiger! They were almost unbeatable until we came out with heavier ones at the end of the war. Did you ever see the Brad Pitt movie called Fury? About tanks and tank battles in WWII?
I have a copy, LOL!
The biggest challenge to the Tiger was the T-34 the Russians made. They copied the Bogey system from a US design, ans added a big gun ans sloping armor; and a star was born!