The Siberian Unicorn
The so-called Siberian unicorn is the best known of the Elasmotherium, a genus of steppe-land rhinoceros that ranged across Eurasia before recorded history. Although no intact horns have yet been found, the large boss on the skull and the muscle hump on the shoulders could have supported a horn as long as a human man. The Yakut people of Siberia have a legend about a large black bull with one horn killed by a spear; the horn was so large and heavy it had to be carried home on a sled. Stories of this one-horned creature may have led to the unicorn legends we have today.
Elasmotherium
Huge beast, unaligned
Armor Class 15 (natural armor)
Hit Points 123 (13d12 + 39)
Speed 40 ft.
STR: 10 (+0), DEX: 10 (+0), CON: 10 (+0)
INT: 3 (-4), WIS: 10 (+0), CHA: 5 (-3)
Senses passive Perception 10
Languages —
Challenge 5 (1,800 XP)
Charge. If the elasmotherium moves at least 20 feet straight toward a target and then hits it with a gore attack on the same turn, the target takes an extra 11 (2d10) piercing damage. If the target is a creature, it must succeed on a DC 17 Strength saving throw or be knocked prone.
Actions
Gore. Melee Weapon Attack: +8 to hit, reach 10 ft., one target. Hit: 17 (2d10 + 6) piercing damage. On a hit, the target must succeed on a DC 14 Constitution saving throw or begin bleeding. Constructs, elementals and undead automatically succeed this saving throw. A bleeding creature loses 5 (1d10) hit points at the start of each of its turns until it uses an action to staunch the bleeding or it receives magical healing.