The Frostbone Titan is an undead sub boss found in Argul's Tomb
The creature ambushes Death at the end of the Frostbone Crypt and must be defeated in order to access the Frigid Spire where Frostbane resides.
The Frostbone Titan is accompanied by several Skeletons although it will often smash them to pieces with its swings. Its attacks are capable of freezing Death and it moves notably faster than the Tormentors encountered in the main storyline. Staying behind the creature will negate most of its attacks and weapons that inflict fire damage will bring it down quickly.