Lego P.1000 Ratte?

[The Wooksta!]

Yep, some lunatic has drawn one up in a Lego design package called Studio.

https://rebrickable.com/mocs/MOC-270065/Phoenix5061/landkreuzer-p-1000-ratte/#details

Mind, the distructions will cost you a fiver, and that's before you have to buy the bits.  Still, the inventory is free, so a bit of common sense and you could probably build it sans instructions.

There's also a Maus to go with it, but the distructions for that one are free.