Jotun

Demigod's Vitality. The jotun's ability scores and hp maximum can't be reduced except by means of a wish spell.

Icy Weapons. The jotun's weapon attacks are magical. When the jotun hits with any weapon, the weapon deals an extra 6d8 cold damage (included in the attack).

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

Material Bound. The jotun is immune to any spell or effect that would force it to leave the Material Plane, unless the jotun wants to leave. It has disadvantage on saving throws against effects that would return it to the Material Plane from another plane of existence.

Too Big to Notice. While the jotun remains motionless in nonmagical, natural terrain, it has advantage on Dexterity (Stealth) checks.

Multiattack. The jotun can use its Frightful Presence. It then makes three Greatclub or Rock attacks.

Greatclub. Melee Weapon Attack: +17 to hit, reach 15 ft., one target. Hit: 28 (4d8 + 10) bludgeoning damage plus 27 (6d8) cold damage.

Rock. Ranged Weapon Attack: +17 to hit, range 60/240 ft., one target. Hit: 32 (4d10 + 10) bludgeoning damage plus 27 (6d8) cold damage.

Frightful Presence. Each creature of the jotun's choice within 120 feet of the jotun and aware of it must succeed on a DC 20 Wisdom saving throw or become frightened for 1 minute. A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. If a creature's saving throw is successful or the effect ends for it, the creature is immune to the jotun's Frightful Presence for the next 24 hours.

Icy Sweep (Recharge 5-6). The jotun swings its ice-coated greatclub in a wide arc. Each creature within 20 feet of the jotun must make a DC 23 Dexterity saving throw. On a failure, a creature takes 36 (8d8) bludgeoning damage and 54 (12d8) cold damage and is pushed up to 15 feet away from the jotun and knocked prone. On a success, a creature takes half the damage and isn't pushed or knocked prone.

Spellcasting. The jotun casts one of the following spells, requiring no material components and using Wisdom as the spellcasting ability (spell save DC 20): At will: earthquake, speak with animals 3/day: bestow curse, gust of wind 1/day: divination

Rock Catching. If a rock or similar object is hurled at the jotun, the jotun can, with a successful DC 10 Dexterity saving throw, catch the missile and take no bludgeoning damage from it.