Avoidance. If Zzek is subjected to an effect that allows her to make a saving throw to take only half damage, she instead takes no damage if she succeeds on the saving throw, and only half damage if it fails.

Legendary Resistance (3/Day). If Zzek fails a saving throw, she can choose to succeed instead.

Turn Immunity. Zzek is immune to effects that turn undead.

Spellcasting. Zzek is a 9th-level spellcaster, her spellcasting ability is Intelligence (spell save DC 14, +6 to hit with spell attacks). +6 to hit with spell attacks). Zzek has the following wizard spells prepared:
Cantrips (at will): mage hand, acid splash, gust

1st level (4 slots): shield, unseen servant, magic missile

2nd level (3 slots): blur, cloud of daggers, misty step, scorching ray

3rd level (3 slots): counterspell, erupting earth, lightning bolt, thunder step

4th level (3 slots): blight, polymorph

5th level (1 slot): cone of cold, wall of force

Callous Crowing. (Recharge 5–6).
Wisdom Save DC 14: Every hostile creature within 90ft. that can hear Zzek makes a Wisdom Saving throw. On a failed save, the target(s) take 2d4 Thunder damage and is frightened until the end of its next turn; half damade on a successful one. All dire chickens within this radius gain a +3 bonus to attack and damage rolls. 

Life Drain Talon. Zzek targets up to two creatures that it can see within 5 feet of her. Each target must succeed on a DC 15 Constitution saving throw or take 10 (2d6) necrotic damage, and Zzek regains hit points equal to the total damage dealt to all targets.

Zzek 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. Zzek regains spent legendary actions at the start of her turn.

Flutter. If Zzek if still in the air at the end of her turn, she flutters to the ground without taking fall damage. 

Cloud of Feathers. Zzek magically poofs into a fluff of feathers Each creature within 10 feet of the demilich, including around a corner, must succeed on a DC 15 Constitution saving throw or be prone with laughter until the end of Zzek's next turn. Anyone that succeeds on the saving throw is immune to this effect for 1 minute.

Frightening Gaze (Costs 3 Actions). Zzek targets one creature it can see within 30 feet of her. The target must succeed on a DC 14 Wisdom saving throw or become frightened for 1 minute. The frightened target can repeat the saving throw at the end of each of their 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 Zzek's gaze for the next 24 hours.