If you kill a frost worm it explodes into a 100' radius of 20d6 damage, some of which is piercing and basically unavoidable. Doesn't that strike anyone as a bit excessive for a CR12 creature. Two frost worms are supposed to be a match for a 14th level party, but when the worms die they could take out a small city.
Maybe they should be changed to fire creatures and renamed tactical-nuke worms.
Maybe they should be changed to fire creatures and renamed tactical-nuke worms.