Colossal Presence. Due to its immense size, the Xixecal ignores all forms of difficult terrain and cannot be forcefully moved.

Innate Spellcasting. The Xixecal's spellcasting ability is Charisma (spell save DC 20, +12 to hit with spell attacks). It can innately cast the following spells, requiring no material components:

• At will: detect magic, haste
• 3/day each: cone of cold, ice storm
• 1/day each: control weather, tsunami

Living Storm. The Xixecal is surrounded by a swirling storm. At the start of each of its turns, and as a reaction when another creature enters its reach, it can deal 14 (4d6) cold damage to each creature within 15 feet of it.

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

Magic Weapons. The Xixecal's weapon attacks are magical.

Regeneration. The Xixecal regains 20 hit points at the start of its turn if it has at least 1 hit point. If the Xixecal takes fire damage, this trait doesn't function at the start of the Xixecal's next turn. The Xixecal dies only if it starts its turn with 0 hit points and doesn't regenerate.

Siege Monster. The Xixecal deals double damage to objects and structures.

Summon White Dragons (5/day). The Xixecal magically summons 1d4+1 adult white dragons. The summoned dragons appear within 60 feet of the Xixecal and act on their own initiative. They remain for 1 hour, until the Xixecal dies, or until the Xixecal dismisses them as a bonus action.

Multiattack. The Xixecal can use its Cold Breath and make two Claw attacks.

Claw. Melee Weapon Attack: +20 to hit, reach 15 ft., one target. Hit: 23 (3d8 + 10) slashing damage plus 14 (4d6) cold damage. If the target is a Large or smaller creature, it is grappled (escape DC 28). The Xixecal can have up to four creatures grappled at a time.

Cold Breath (Recharge 4-5). The Xixecal exhales a blast of frigid air. Each creature in a 90-foot cone must make a DC 28 Constitution saving throw. On a failed save, a creature takes 77 (22d6) cold damage and is restrained for 1 minute. On a successful save, a creature takes half the damage and isn't restrained. A creature restrained by this breath can use its action to make a DC 28 Strength (Athletics) or Dexterity (Acrobatics) check to escape.

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

•  Attack. The Xixecal makes one Claw attack.
•  Stomp (Costs 2 Actions). The Xixecal stomps the ground. Each creature within 15 feet of the Xixecal must succeed on a DC 26 Dexterity saving throw or take 28 (4d10 + 10) bludgeoning damage and be knocked prone.
• Absolute Zero (Costs 3 Actions). The Xixecal unleashes a wave of intense cold. Each creature within 60 feet of the Xixecal must make a DC 28 Constitution saving throw, taking 35 (10d6) cold damage on a failed save, or half as much damage on a successful one.