Burrowing Behemoth
From Warhammer - The Old World - Lexicanum
Burrowing Behemoths are a giant Skaven monstrosity, used as living tunneling tools.
Overview
The vast, balding monstrosities that burrow blindly in the deepest tunnels of Hell Pit were originally pioneered as a way of expanding Clan Moulder's subterranean empire. However these blind and twisted beasts are no less effective in battle, bursting from the earth and smashing into the enemy with earth-shaking force.
Sources