Ancient Golden Moose

Spellcasting. The Ancient Golden Moose is an 20th-level spellcaster. Its spellcasting ability is Wisdom (spell save DC 25, +17 to hit with spell attacks). The Moose has the following spells prepared:

Dominate person: The Ancient Golden Moose attempts to take over it's target. The target must succeed on a DC 25 wisdom saving throw if it succeeds the Ancient Golden Moose must concentrate can cannot take any other action or the spell is broken

True Polymorph: The Moose attempts to change the form of the target, the target needs to succeed an DC25 wisdom saving throw if the target fails the Moose changes the targets form the target cannot change to anything larger than it or to anything that has a  challenge rating higher than 9 this is a concentration spell . If the moose concentrates for more than an hour the spell is permanent 

Multiattack. The Moose can use its Frightful Presence. It then makes three attacks: 

Sun Beam: The Ancient Golden Moose uses the power of the sun and launches a beam of pure energy at a 80 by 80 feet square the target must save on a DC 23 Constitution saving throw and take 10 D12 fire damage on a failed save and take half on a successful one.

Antler Ram : The ancient Golden Moose rams into it's enemies with it's antlers that are sharper than the most powerful swords. Melee Weapon Attack +16 to hit, reach 40 ft., ten targets. Hit: 12 D10+9 piercing damage.  The Targets must also succeed on a DC 29 Strength Save or be knocked 40 feet and prone

Frightful Presence. Each creature of the Ancient Golden Moose's choice that is within 120 feet of the Moose and aware of it must succeed on a DC 24 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 Moose's Frightful Presence for the next 24 hours.

 The Ancient Golden Moose 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. The dragon regains spent legendary actions at the start of its turn.

Invisibility(cost 2 actions): The Golden Moose cast the invisibility spell

Teleport:The Golden moose teleports to anywhere it sees(Including the air)

Attack: The moose attacks with one of it's attacks