Mikillhorn

The Mikillhorn is a large herbivore from the far north, known for its prominent horn attached to its nose and for their surprising speed and endurance for their size and build.
By nature, Mikillhorn tend to be much more solitary and are only seen with other Mikillhorn while mating or raising young. As a solitary herbivore, this makes it seemingly an easy target for predators. Because of this, Mikillhorns tend to be extremely territorial driving off even other herbivores that get too close.
Once antagnoized, the Mikillhorn seemingly transforms into a living battering ram, using its overwhelming size and surprising speed skewer its foes with its horn. Unlike other hertbivores which flee when wounded, the Mikillhorn would rather stand its ground than flee as its fury gives its unnatural endurance letting it shrug off the harshest of wounds.
Because of this, many predators tend to leave Mikillhorn alone for it will be a prolonged and dangerous endeavor to bring one down. Their tenacity also makes them a prized mount for some; if they have the courage and discipline to attempt to tame such an unruly beast.

Mikillhorn CR: 5 (1,800 XP)

Large beast, unaligned

Armor Class: 11 (natural armor)

Hit Points: 105 (10D10+50)

Speed: 40 ft

STR

21 +5

DEX

8 -1

CON

20 +5

INT

2 -4

WIS

12 +1

CHA

6 -2

Skills: Athletics +8, Perception +4

Damage Resistances: Cold

Senses: passive Perception 14

Challenge Rating: 5 (1,800 XP)

Siege Monster. The Mikilhorn can deal double damage to buildings and structures.
Ice Walk. The Mikilhorn 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.
Reckless. At the start of its turn, the Mikilhorn can choose to have advantage on its attack rolls. Attacks against it have advantage until the start o fits next turn
Charge. If the Mikilhorn moves at least 20ft. straight towards a creature and then hits it with a gore attack on the same turn, the target takes an additional 13(2d12) damage.
Aggressive. The Mikilhorn can move up to its movement speed as a bonus action to move towards a hostile creature
Relentless. If the Mikilhorn is reduced to 0 hitpoints, it can make a DC 10 Constitution saving throw. If it succeeds, it drops to 1 hitpoint instead. Each time it uses this feature after the first, the DC increases by 5. The DC resets to 10 after a short or long rest.

Actions

Gore. Melee Weapon Attack, +8 to hit , 5ft., one target. Hit: 18 (2d12+5) piercing damage. If the target is a creature, it must succeed a DC 16 Strength saving throw or be knocked prone on a failed save. As a bonus action, it can gore a creature that is knocked prone
Stomp. Melee Weapon Attack: +8 to hit, reach 5 ft., one prone creature. Hit: 13 (2d6 + 6) bludgeoning damage