Magic Resistance. The Aspect of Merrshaulk has advantage on saving throws against spells and other magical effects.

Two Heads. The Aspect of Merrshaulk has advantage on saves against being blinded, charmed, deafened, frightened, stunned, or knocked unconscious.

Rejuvenation.  If this creatures hitpoints are reduced by 75 points, one head of it is decapitated. It will regrow at the end of it's next turn healing 30 hitpoints, if at least one head is still in place. If it dies, the Aspect of Merrshaulk returns to life in 1d6 days and regains all its hit points. Its maximum hitpoints will be increased by 60 points total. Only a wish spell can prevent this trait from functioning.

Multiattack. The anathema makes up to two Flurry of Bites attacks.

Flurry of Bites. Melee Weapon Attack: +10 to hit, reach 10 ft., one creature. Hit: 27 (6d6 + 6) piercing damage plus 14 (4d6) poison damage.

Constrict. Melee Weapon Attack: +10 to hit, reach 15 ft., one Large or smaller creature. Hit: 12 (2d6 + 6) bludgeoning damage and the target is grappled (escape DC 16). Until this grapple ends, the target is restrained, and it takes 12 (2d6 + 6) bludgeoning damage at the start of each of its turns. The Aspect of Merrshaulk can constrict only one creature at a time.

Spellcasting. The Aspect of Merrshaulk casts one of the following spells, if it had only done one melee attack in this round, requiring no material components and using Charisma as the spellcasting ability (spell save DC 17):

At will: animal friendship (snakes only)

3/day each: darkness,  fear, polymorph, suggestion, flesh to stone

2nd level (3 slots): detect thoughts, hold person

3rd level (3 slots): lightning bolt, water breathing

4th level (3 slots): blight, dimension door

5th level (2 slots): dominate person

The Aspect of Merrshaulk can take 3 legendary actions, using the options below. It can take only one legendary action at a time and only at the end of another creature’s turn. The beholder regains spent legendary actions at the start of its turn.

Ophidiophobia Aura. Any creature of the apects choice that can see it, other than a snake or a yuan-ti,  must succeed on a DC 17 Wisdom saving throw or become frightened of snakes and yuan-ti. A frightened target can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. If a target’s saving throw is successful or the effect ends for it, the target is immune to this anathama’s aura for the next 24 hours.

Cone of Anti-magic. The Aspect of Merrshaulk can create a 15 feet cone of antimagic from the point of one of it's heads. When created, it can change the direction of the cone using another legendary action. The Cone of Anti-Magic is automatically dismissed if it decides to use the Bite Action. Every spell or magic property wich enters the area of the effect is dispelled as it is targeted by the dispel magic spell. The magic propertys of such an item will come back at the end of the next turn.