Slitherine

See that German tank? If you look, the tech level of the unit is 19, so I am guessing that it's something hypothetical that was never actually built? Sure startled the heck out of me. If you look at the relative tech levels of my armor units in the pic, (8-12), you can see maybe why I was a little nervous.

Fortunately, I have enough air power handy to bomb any one unit back into the stone age

It's a Maus [Mouse] - it was much larger even than a King Tiger (I believe the secondary co-axial weapon was a 75mm, the same size as a Sherman's main gun). The Germans were developing it at the end of the war, I seem to remember they built two of them but one wasn't finished and the other broke down on the way to the front and they blew it up themselves. See http://en.wikipedia.org/wiki/Panzer_VIII_Maus

Interesting Article!