Frost Jötunn Jarl

Frost Jötunn Jarl CR: 17 (18,000 XP)

Huge jötunn, chaotic evil

Armor Class: 18 (magical heavy hide)

Hit Points: 232 (19D12+108)

Speed: 40 ft

STR

26 +8

DEX

14 +2

CON

22 +6

INT

13 +1

WIS

17 +3

CHA

19 +4

Saving Throws: Strength +11, Constitution +11, Wisdom +7, Charisma +10

Skills: Athletics +16, Intimidation +12, Perception +9

Damage Vulnerabilities: Fire

Damage Resistances: Force, Lightning, Poison, and Thunder

Damage Immunities: Cold

Condition Immunities: Charmed, Frightened

Senses: darkvision 60 ft., Passive Perception 19

Languages: Jötun, Astari

Challenge Rating: 17 (18,000 XP)

Bloodied Berserker. If the Frost Jötunn Jarl starts its turn below half it's hitpoint maximum, whenever it takes the Attack action, it can make one additional attack with its Frozen Greataxe as part of that action.
Brutal. If the Frost Jötunn Jarl deals a critical hit, it can triple the damage die instead of doubling it.
Endurance. If the Frost Jötunn Jarl fails a Constitution saving throw against an effect that deals damage, he takes half damage and none on a success.
Giant's Might. The Frost Jötunn Jarl can deal a critical hit on a 18-20 against creatures at least one size smaller than him.
Ice Stride. The Frost Jötunn Jarl can move through icy or snowy terrain without having to make an ability check or expend additional movement.
Siege Monster. The Frost Jötunn Jarl can deal double damage to buildings and objects.
Snow Sight The Frost Jötunn Jarl's vision is not obscured by heavy snowfall or fog.
Titanic Strength. The Frost Jötunn Jarl has advantage on Strength ability checks and saving throws against creatures at least one size smaller than him.
Aggressive. The Frost Jötunn Jarl can use its bonus action to move up to its movement speed towards a hostile creature that it can see within range. The Frost Jötunn Jarl must end this movement closer to a hostile creature from where it started.
Innate Spellcasting. The Frost Jötunn Jarl's spellcasting ability is Charisma (Spell save DC 18, +10 to hit with spell attacks). Frost Jötunn Jarls can innately cast the following spells, requiring no material components:

• Cantrips (At Will):
  Darkness, Minor Illusion, Misty Step, Ray of Frost

• 3/day each: Charm Person, Cone of Cold, Counterspell, Detect Magic, Dispel Magic, Enthrall, Gust of Wind, Major Image

• 1/day each: Cone of Cold, Freezing Sphere, Wall of Ice

Change Shape. The Frost Jötunn Jarl magically Polymorphs into a medium sized human form that has a challenge rating no higher than its own, or back into its true form. It reverts to its true form if it dies. Any equipment it is wearing or carrying is absorbed or borne by the new form.
In the human form, King Glaumarr retains his alignment, hit points, Hit Dice, proficiencies, Legendary Resistance, lair actions, and Intelligence, Wisdom, and Charisma scores, as well as this action.

Actions

Multiattack. King Glaumarr can make two attacks with his Frozen Greataxe.
Frozen Greataxe. Melee Weapon Attack: +11 to hit, reach 5 ft., one target. Hit: 26 (4D8 + 10) bludgeoning damage plus 17 (6d6 +5) cold damage.
On a hit, a Large or smaller target must succeed a DC 20 Strength saving throw or be knocked prone.
Icy Rock. Ranged Weapon Attack: +10 to hit, 60/240ft., one target. Hit 27(4d10+5) bludgeoning damage + 18(4d8) cold damage. On a hit, the target must succeed a DC 20 Strength saving throw or be knocked prone and restrained. Creatures restrained in this manner must use its action to break free with a

Reactions

Rampage. When King Glaumarr reduces a creature to 0 hitpoints, it can use its reaction to move up to half its movement speed and make a Frozen Greataxe attack against a creature within range.
Retaliation. If a creature hits King Glaumarr with a melee attack while within 10ft. of it, King Glaumarr can make an attack with his Frozen Greataxe.