Arrgath the Inkless

Undead: Creature does not need to eat, sleep or breathe.

Undead Fortitude. If damage reduces Arrgath the Inkless to 0 hit points, it must make a Constitution saving throw with a DC of 5+the damage taken, unless the damage is radiant or from a critical hit. On a success, the zombie drops to 1 hit point instead.

Eight Armed. Arrgath the Inkless can attack with each of his tentacles independently, engaging up to eight targets at once regardless of direction.

Tentacles: Melee Weapon Attack: +5 to hit, reach 15 ft., one target. Hit: (2d6 + 3) bludgeoning damage.

Flailing Lash: Arrgath the Inkless makes a tentacle attack against up to eight targets within reach. 

Arrgath the Inkless 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 lich regains spent legendary actions at the start of its turn.

Tentacles: Melee Weapon Attack: +5 to hit, reach 15 ft., one target. Hit: (2d6 + 3) bludgeoning damage.

Lich Call (Costs 2 Actions): Arrgath the Inkless can summon a single Lich Eel

Frightening Gaze: Arrgath the Inkless fixes its gaze on one creature it can see within 10 feet of it. The target must succeed on a DC 18 Wisdom saving throw against this magic or become frightened for 1 minute. The 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 the Arrgath the Inkless' gaze for the next 24 hours.