Monster Stat #17:  the juggernaut
  (from Adventurers #59-60 and #233-234)

frequency             Unique
climate/terrain       underground (specifically, the lost Suel city beneath the Suss Forest)
movement              see below
armor class           -4
HD                    16 (128 hp)
thac0                 7
# of attacks          1 + 1-6
damage/attack         10-60 ramming/roll over + 3-18 per side ram
special attacks       ramming
special defenses      see below
magic resistance      none
intelligence          Non-
alignment             neutral
size                  H (30' long, 20' wide, 10' high)

  This huge, fearsome construct is composed entirely of magical stone.
Unique in nature, it was fashioned by the Sueloise several centuries ago
and left to guard valuables in one of their sunken cities.
  The juggernaut is able to sense all movement within a 300' radius,
and its programming is simple:  crush anything within range.
  The juggernaut is slow to get moving, beginning at a 3" movement rate.
The second round of movement, it rolls along at a 6" clip...and so on,
to a maximum speed of 15".  If it rolls over an opponent, that foe
(as well as each of its possessions) must save vs. crushing blow or be
destroyed.  Opponents at the construct's flanks are subject to 1-3
attacks (each side) from the juggernaut's side rams.  These are each
carven in the shape of an animal head (goat, lion, eagle.)  The
juggernaut is immune to slow spells and takes only half damage from fire,
cold, and electricity attacks as well as edged weapons.  The best way to
immobilize it proved to be a rock-to-mud spell directly beneath it.