Glacial Worm

When a glacial worm is in extreme cold or surrounded by ice, it gains fast healing 10. When struck by a magical cold effect, a glacial worm regains Hit Points equal to half the cold damage the effect would otherwise deal.

The glacial worm recovers from the Paralyzed, Slowed, and Stunned conditions at the end of its turn. It's also immune to penalties to its Speeds and the Immobilized condition, and it ignores difficult terrain and greater difficult terrain.

30 feet. A glacial worm's intense cold absorbs heat. Creatures that start their turn within the area take 3d6 cold damage (DC 34 fortitude save).

Frequency once per day

Trigger The glacial worm would be affected by a condition or adverse effect (such as baleful polymorph )

Effect The glacial worm negates the triggering condition or effect. Effects from artifacts, deities, or a similarly powerful source can't be avoided in this way.

Trigger The worm Grabs a creature

Effect The worm uses Swallow Whole.

Huge, (3d8+12)[bludgeoning,2d6 cold], Rupture 28

The worm makes a Strike once against each creature in its reach. It can Strike up to once with its jaws and any number of times with its body. Each attack counts toward the worm's multiple attack penalty, but the multiple attack penalty doesn't increase until after it makes all the attacks.