Apex Goss Harag

Enrage (Mythic Trait). When the goss harag is reduced to half of its maximum hit points, it immediately saves against all ongoing conditions and effects and gains 1 extra turn in the initiative order (roll initiative again to determine when its second turn occurs). The experience for fighting an enraged goss harag is 1.5x its standard XP value.

Ice Walk. The goss harag can move across and climb icy surfaces without needing to make an ability check. Additionally, difficult terrain composed of ice or snow doesn't cost it extra movement.

Keen Smell. The Goss Harag has advantage on Wisdom (Perception) checks that rely on smell.

Legendary Resistance (3/Day). When the goss harag fails a saving throw, it can choose to succeed, instead.

Lord of the Mountain. The goss harag permanently retains the benefits of the Speak with Animals spell, and can communicate with monstrosities with its effects as well.

Magic Resistance. The goss harag has advantage on saving throws against spells and other magical effects.

Rage of the Beast. The Goss Harag has its veins turn bright red when angry and a frosty blue when it is calm. Its mood changes every minute. Apply the following effects, depending on the Goss Harag's mood:

• Angry Red. When the Goss Harag hits a creature with an attack, it must succeed on a DC 16 Constitution saving throw or be frightened of the Goss Harag for 1 minute. A creature can repeat the saving throw at the end of each of its turns, ending the effect on a success. The Goss Harag has advantage on attack rolls against frightened targets.
• Calm Blue. When the Goss Harag hits a creature with a weapon attack and it rolls a 20 on the attack roll, the Goss Harag deals an additional 35 (10d6) cold damage on a hit and the ground under the target and in a 5-foot radius around it becomes difficult terrain made of ice.

Resourceful. When a creature imposes disadvantage on the goss harag's rolls, it gains a +8 bonus to it next roll that has disadvantage.

Snow Camouflage. The goss harag has advantage on Dexterity (Stealth) checks made to hide in snowy terrain.

Standing Leap. The goss harag's long jump is up to 45 feet and its high jump is up to 30 feet, without a running start. In addition, the goss harag does not incur opportunity attacks while moving with a jump.

The Limb Reaper. The goss harag's weapon attacks that deal slashing damage are magical for the purpose of overcoming resistance and immunity to nonmagical attacks. Additionally, its weapon attacks that deal slashing damage are treated as if they were attacks from a Sword of Wounding (DC 20). When the goss harag hits a creature on an attack roll of 16 to 20, it can apply one of the following magic weapon effects to its attack, as if it rolled a 20 on the d20: 

• 16 or 17: sword of sharpness
• 18 or 19: vorpal sword
• 20: The goss harag chooses which weapon effect to apply.

The Ice Demon. The goss harag's weapon attacks ignore resistance to slashing and/or cold damage. A creature that takes cold damage from the goss harag has its movement speed reduced by 10 feet until the end of its next turn. A creature that takes slashing damage form the goss harag has disadvantage on all attack rolls until the start of the goss harag's next turn.

Multiattack. The Goss Harag makes three weapon attacks. It can replace one weapon attack for an Uppercut or two for its Cold Breath.

Bite (1/Turn). Melee Weapon Attack: +17 to hit, reach 10 ft., one target. Hit: 25 (4d8 + 9) piercing damage plus 11 (2d10) cold damage. The goss harag regains hit points equal to the inflicted piercing damage. If the goss harag has an ice weapon, it can make one ice sword attack or ice wrecking ball attack as a part of this attack.

Fist. Melee Weapon Attack: +17 to hit, reach 10 ft., one target. Hit: 19 (2d10 + 9) bludgeoning damage and is knocked prone. If the goss harag has two ice swords, it can't make this attack. While covered in an ice wrecking ball, the goss harag makes the following attack with its fist, instead:

• Ice Wrecking Ball (Requires Wrecking Ball). Melee Weapon Attack: +17 to hit, reach 10 ft., one target. Hit: 27 (3d12 + 9) bludgeoning damage plus 21 (6d6) cold damage and is knocked prone. A creature hit by this attack must succeed on a DC 25 Dexterity saving throw or be stunned until the end of its next turn. This attack deals triple damage to objects and structures.

Ice Sword (Requires Sword). Melee Weapon Attack: +17 to hit, reach 15 ft. (or 10 ft. when broken), one target. Hit: 24 (3d10 + 9) slashing damage plus 14 (4d6) cold damage or 22 (3d8 + 9) slashing damage plus 7 (2d6) cold damage when the sword is broken. When the Goss Harag makes this attack, it can apply one of the following options to the attack:

• Quick Slashes. The Goss Harag swings low diagonally in front of it, making an attack roll with its ice sword against each creature within 15 ft. of the goss harag in the direction its facing. While equipped with an ice sword an wrecking ball, it performs this twice, making an Ice sword and Ice wrecking ball attack against each creature in that area. When equipped with two Ice Swords, it can perform this up to 3 times in succession, making three ice sword attacks against all creatures in that area. If it does, attacks against the goss harag will have advantage until the end of its next turn.
• Blade Skewer. Goss Harag plunges its blade into the ground in front of it, attempting to skewer the target. The ice sword attack deals piercing damage instead of slashing on a hit, and each creature within 5 feet of the target (excluding the goss harag) takes piercing damage equal to half of the piercing damage the target took.
• Whirling Strikes (Requires two swords). The Goss Harag winds up by bending down and pulling back its weapons to one side and then attacking explosively as it swings its weapons in a whirling motion, making an attack against each creature within 15 ft. of it.
• Meat Cleaver. The Goss Harag raises its Ice Blade arm and sends it crashing straight down in front of it, making an ice sword attack against each creature in a 15-foot-line that is 5 feet wide. On a hit, this attack is an automatic critical hit and knocks a creature prone until the end of its next turn. The Goss Harag may leap towards its target if they within its long jump before landing the strike.
• Double Meat Cleaver (Requires two swords). The Goss Harag performs a large downward chop with one blade and then quickly follows up with the other, making two ice sword attacks against each creature in a 15-foot-line that is 5 feet wide. A creature hit by this attack must succeed on a DC 25 Constitution saving throw or be stunned for 1 minute. After making this attack, attacks against the goss harag have advantage until the end of its next turn.
• Frost Shards. At the cost of its weapons' integrity, the Goss Harag swings violently, splintering its weapons and sending shards of ice flying at its target, making a throw ice weapon attack at half damage and half the range. An Ice weapon loses 5 hit points each time the goss harag uses this option.

Throw Ice Weapon (Requires Sword). Ranged Weapon Attack: +17 to hit, range 90/270 ft., one target. Hit: 27 (3d12 + 9) bludgeoning damage plus 21 (6d6) cold damage for the ice wrecking ball, 24 (3d10 + 9) slashing damage plus 14 (4d6) cold damage for the ice sword, or 14 (2d8 + 9) slashing damage plus 7 (2d6) cold damage when the sword is broken. The sword is destroyed on a hit or miss. If the Goss Harag hits a flying target with this attack, it must succeed on a DC 25 Constitution saving throw or be knocked unconscious for 1 minute. The unconscious target will awaken if it takes damage or another creatures uses its action to wake it up.

Cold Breath (Recharge 5-6). The goss harag exhales frigid air in a 120-foot line that is 10 feet wide followed by another blast of frigid air in a 60-foot cone, centered on the line. Each creature in that area must make a DC 20 Constitution saving throw, taking 70 (13d10) cold damage on a failed save, or half as much damage on a successful one.

Uppercut. The goss harag makes one fist attack against a creature. If the attack hits, the creature takes an extra 36 (8d8) bludgeoning damage. If the target is a Medium or smaller creature, it is launched 40 feet into the air before it falls prone in a space 20 feet away from the goss harag, taking 7 (2d6) bludgeoning damage for every 10 feet it fell.

Create Ice Weapons. Immediately after the goss harag uses its cold breath, it can create a blade or wrecking ball made of ice on one or both of its fists. An ice sword and/or wrecking ball be attacked and broken (destroyed in the case of wrecking ball; sword AC 20/wrecking ball AC 25; sword hp 60/ wrecking ball hp 90; vulnerability to fire and magic bludgeoning damage; immunity to cold, poison, and psychic damage). Breaking a sword deals no damage to the goss harag, and becomes a broken sword. A broken sword deals half as much damage as an ice sword (included in the attack). It can be attacked and destroyed (AC 20; hp 30; vulnerability to fire and bludgeoning damage; immunity to cold, poison, and psychic damage). Destroying a sword or wrecking ball deals no damage to the goss harag. While enraged, the goss harag also creates an [spell]Armor of Agathys[/monster] (9th level) around itself.

Execute. After the goss harag makes an ice sword attack using its Meat Cleaver or Double Meat Cleaver options, it takes on a tall, menacing stance as it slowly walks towards a creature that was stunned by the attack, moving at half speed. When it reaches its target, it executes them with a deliberate downward strike with its left blade. This attack deals an additional 78 (26d6) slashing damage.

Master of the Wild. The goss harag uses the Commune with Nature spell.

Crushing Blow. When the goss harag hits a creature with its uppercut, it can prepare a massive blow. Until the start of its next turn, its movement is reduced to 0 and it can't use its jump legendary action. At the start of its next turn, if the target of the uppercut is still within 10 feet of the goss harag, the goss harag makes one Fist or Ice Sword attack against the target. On a hit, the creature takes an extra 28 (6d8) weapon damage and the area in a 10- foot radius around the target becomes icy difficult terrain.

The goss harag can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another creature's turn. The goss harag regains spent legendary actions at the start of its turn.

Attack. The goss harag makes one weapon attack.

Jump. The goss harag jumps up to 60 feet away.

Ground Smash (Costs 2 Actions). The goss harag smashes its fist on the ground, creating difficult terrain in a 30-foot line that is 5 feet wide. Each creature in line must make a DC 25 Dexterity saving throw, taking 44 (8d10) bludgeoning damage on a failed save, or half as much damage on a successful one.

Rampage (Costs 2 Actions). The goss harag makes five weapon attacks.

If the Goss Harag is enraged, it can use the following options as legendary actions.

Cold Breath. The goss harag recharges its breath weapon and uses it. The line of the goss harag's cold breath becomes a wall of ice that is 10 feet tall and fills the area of the line.

Uppercut. The goss harag uses its uppercut.

Roar of the Apex (Costs 3 Actions). The goss harag roars, calling in its subjects to fight for it. 1d12 + 10 polar bears, 1d10 + 8 Winter Wolves, 1d8 + 6 Abominable Yeti's, 1d6 + 4 Frost Salamanders, or 1d4 Remorhaz will appear within 90 feet of the goss harag after 1d4 rounds (the goss harag's choice). They roll for initiative as seperate groups, one for each different creature, and fight to the death. The goss harag can't use this legendary action until the previously summoned creatures are dead.