Once in a great while, a frost giant is born who will strike fear throughout the northern tundra. Thrag is one such giant, and he stands nearly 17 ft. tall. He has skin as gray as smoke and eyes as black as coal. The lore about him is such that any giant that has such physical characteristics sends any but the most stalwart of heroes fleeing. Thrag takes no prisoners and destroys for the pleasure of it.
Thrag Ice-Breaker  CR 12
CE Large half-fiend native outsider (cold, giant)
Init +1; Senses low-light vision, darkvision 60 feet; Perception +10
DEFENSE
AC 24, touch 11, flat-footed 23 (+4 armor, +1 Dex, +10 natural, –1 size)
hp 161 (14d8+98)
Fort +14, Ref +3, Will +6
Defensive Abilities rock catching; immunity to poison; acid, cold, electricity, and fire resistance 10
Weaknesses vulnerability to fire
OFFENSE
Speed 40 ft.
Melee greataxe +21/+15 (3d6+16/x3) or 2 slams +21 (1d8+9)
Mountain Breaker +23/+18 (3d6+18/x3) [see below]
Ranged rock +11 (1d8+13)
Space 10 ft.; Reach 10 ft.
Special Attacks rock throwing (120 ft.); smite good
Spell-Like Abilities
1/day—contagion, desecrate, unholy blight
3/day—darkness, poison
STATISTICS
Str 33, Dex 12, Con 25, Int 12, Wis 16, Cha 13
Base Atk +10; CMB +22; CMD 33
Feats Cleave, Great Cleave, Improved Overrun, Improved Sunder, Martial Weapon Proficiency (greataxe), Power Attack, Skill Focus (Stealth)
Skills Climb +13, Craft (any one) +7, Intimidate +7, Perception +10, Stealth +2 (+6 in snow); Racial Modifiers +4 Stealth in snow
Languages Common, Giant
SPECIAL ABILITIES
Smite Good (Su) Once per day, as a swift action, Thrag can smite good as the smite evil ability of a 14th-level paladin, except affecting a good target. The smite persists until target is dead or Thrag rests.
Mountain Breaker (+ 2 greataxe of dwarf bane) This axe is crafted from the arms and armor of one of the frost giants’ most hated enemies: the dwarves. Its blade is an amalgamation of dwarven armor pieces and broken weapons forged into a greataxe. Only the fiercest and most courageous frost giants wield this axe. In frost giant culture, this weapon is never given to another—it is taken from the hands of dead former wielders.
Plot Hook: Mountain Breaker has recently been spotted in the hands of a very powerful frost giant raider named Thrag Ice-Breaker. Word of this has gotten back to the dwarven king, who has promised anybody who returns the axe to him a vast reward of gold and gems.
I like Mountain Breaker! Forge welded goodness and totally realistic.