Gorgon Armored Assault Transport
The Gorgon Armored Assault Transport is the Imperial Guard's largest ground transport, capable of carrying a full fifty men. It was built with one purpose in mind: to move a large volume of soldiers right up to a heavily fortified enemy position. Which translates into the throwing the guardsmen into whatever the fuck they encounter and hope by raw pluck, ingenuity or raw numbers they succeed. It is especially suited for trench warfare, with a nearly invulnerable prow that lets it glide over no-man's-land. It is also open-topped, which makes it unsuitable for longer-duration missions -- standard doctrine is to suppress the enemy with artillery fire, rush the Gorgons across the gap, and deploy the troops before the enemy has a chance to respond. (Think of the Higgins boats used in WWII and Korea but driving about on treads.)
The Death Korps of Krieg are the most prevalent users of this vehicle, as it works best in their style of engagement. It also fits in with their suicidal deathwishes, what with the thing having no armour on top and all.
It seems to share some features with the Macharius Heavy Tank chassis.