Burrow. Sandworms can freely move through solid material of SOAK 5 or less at half their SPEED.
Devastation. Anywhere a sandworm has passed becomes difficult terrain. The sandworm itself is immune to the effects of difficult terrain.
Acid blood splash. Any melee attack which successfully bypasses the sandworm's SOAK with slashing or piercing damage causes 2d6 acid damage to the attacker.
Swallow whole. A sandworm automatically swallows a large or smaller creature whole when making a bite attack. The creature takes 4d6 acid damage each round while inside the sandworm. Escape requires a single melee attack against the sandworm which does 30 damage. The sandworm's SOAK does not apply from within.