big nosed purple monster

Aura of Frost. The ground within 20ft of Marran freezes over, becoming difficult terrain. Creatures who move at more than half speed over the ground must succeed on a DC 16 Dexterity saving throw to stay on their feet and lose their action for the turn.

Plants within 60ft of Marran wither and non-magical fires smaller than 5 ft are snuffed out. They spring back to life once their are no longer within range.

Marran is not affected by difficult terrain caused by ice.

Sheer Cold. A creature that touches Marran or hits it with a melee attack while within 5 ft of it takes 10 (3d6) cold damage.

If a creature has been grappled by Marran for a number of rounds equal to its constitution modifier, or falls unconscious while it is being grappled, it freezes and becomes paralyzed. In order to thaw out it must spend a short rest within 5 ft of an open flame. The creature suffers 1 point of exhaustion when it freezes and an additional point for every hour it has spent frozen after that. If the creature remains frozen for 5 hours it dies.

Icy Screech. Marran lets out an ear tearing screech. Creatures who can hear it must succeed on a DC 16 Wisdom saving throw or be frightened of Marran for 1 minute. Creatures may repeat the saving throw at the end of their turns, ending the effect on a success.

Multiattack. Marran makes three attacks with its slam, or one with slam and one with grab.

Slam. Melee Weapon Attack: +10 to hit, reach 5 ft., one target. Hit: 14 (2d8 + 5) bludgeoning damage plus 7 (2d6) cold damage. 

Grab. Melee Weapon Attack: +10 to hit, reach 5 ft., one target. Hit: 12 (2d6 + 5) bludgeoning damage and the target is grappled (escape DC 18). Until the grapple ends the target is restrained and takes 14 (4d6) cold damage at the beginning of its turns until the grapple ends. While it has a creature grappled in this way Marran can use Grab to damage that creature or it can use Icy Screech.