Legendary Resistance (3/Day): If Zarmot fails a saving throw, it can choose to succeed instead.

Magic Resistance: Zarmot has advantage on Saving Throws against Spells and other magical Effects.

Magic Weapons. Zarmot weapon attacks are magical.

Immutable Form. Zarmot is immune to any spell or effect that would alter its form.

Reflective Carapace: Whenever Zarmot has taken damage from spells roll a d6. On 1-5 the damage is cut in half. When roll a 6 the damage is deflected and no damage is done.

Siege Monster: Zarmot deals double damage to Objects and structures.

Winds of Change. Zarmot take control of the weather within 10 miles of Zarmot for the duration. It must be outdoors for this ability to work. Moving to a place where you don’t have a clear path to the sky ends.
Zarmot change the current weather conditions, which are determined by the DM based on the climate and season. You can change precipitation, temperature, and wind. It takes 1d4 × 10 minutes for the new conditions to take effect. Once they do so, you can change the conditions again. The after effects of this ability can only be removed with a wish spell.
When you change the weather conditions, find a current condition on the following tables and change its stage by one, up or down. When changing the wind, you can change its direction.
Precipitation
Stage Condition
1 Clear
2 Light clouds
3 Overcast or ground fog
4 Rain, hail, or snow
5 Torrential rain, driving hail, or blizzard

Temperature
Stage Condition
1 Unbearable heat
2 Hot
3 Warm
4 Cool
5 Cold
6 Arctic cold

Wind
Stage Condition
1 Calm
2 Moderate wind
3 Strong wind
4 Gale
5 Storm

Multiattack. Zarmot can use is frightful Presence. Then makes three attacks: two with its claws and one with its bite or tail.

Bite. Melee Weapon Attack. +19 to hit, reach 15 ft., one target. Hit: 36 (4d12 + 10) piercing damage. 

Claws. Melee Weapon Attack. +19 to hit, reach 10ft., one target. Hit: 24 (4d6 + 10) slashing damage.

Tail. Melee Weapon Attack. +19 to hit, reach 20ft., one target. Hit: 32 (4d10 + 10) bludgeoning damage and the target must make a DC 22 Strength saving throw or
knocked prone.

Breath of Chaos (Recharge 5-6). Roll a d4 each time you use this action to determine what element Zarmot exhales. On a 1, fire damage; On a 2, cold damage; On a 3, necrotic; On a 4, lightning. Zarmot exhales the rolled element in a 120-foot line that is 10 feet wide. Each creature in that line must make a DC 22 Dexterity saving throw or take 63 (18d6) (of the rolled elemental) damage on a failed save, or half as much damage on a successful one.

Frightful Presence. Each creature of Zarmot choice within 240 feet of it and aware of it must succeed on a DC 22 Wisdom saving throw or become Frightened for 1 minute. A creature can repeat the saving throw at the end of each of its turns, with disadvantage if Zarmot is within line of sight, 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 Zarmot Frightful Presence for the next 24 hours.

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

Fly. Zarmot flies up to half its fly speed without provoking opportunity attacks.

Detect. Zarmot makes a Wisdom (Perception) check.

Storm of Discord.(Cost 2 Action) Roll a d4 each time you use this action to determine what element in a 120-foot radius around Zarmot. On a 1, fire damage; On a 2, cold damage; On a 3, necrotic; On a 4, lightning. All creatures must make a DC 22 Dexterity saving throw, taking 22 (4d10) (of the rolled elemental) damage on a failed save, or half as much damage.