Long. Aamos spans 75x15ft. Each segment is a 10x10 Block. As he moves, the segments move up with him, trailing behind if he turns.

Host of Pestilence. He is surrounded by an aura of pestilence. Every creature in a 20ft radius must succeed a DC 16 Con-Save or be poisoned until the end of their turn. If a corpse is in a 15ft radius around Aamos at the start of his turn, he heals 20hp and the corpse is consumed.

Ruler of Forlon. Aamos has control over all diseased people in Forlon. As a bonus action, he can command one of his subjects to attack during Aamos' turn.

Undead Fortitude. If Aamos would be reduced to 0 hit points,  he 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 Aamos drops to 1 hit point instead.

Legendary Resistance (1/Day). If the creature fails a saving throw, it can choose to succeed instead.

Spellcasting. The naga is a 10th-level spellcaster. Its spellcasting ability is Intelligence (spell save DC 14, +8 to hit with spell attacks), and it needs only verbal components to cast its spells. It has the following wizard spells prepared:

Cantrips (at will): mage hand, minor illusion, Infestation

1st level (4 slots): charm person, detect magic, sleep

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

3rd level (3 slots): black tentacles, bestow curse

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

5th level (2 slots): dominate person

Multiattack. Aamos makes 2 Attacks, one with his Bite and one with his tail. Then he uses his Necrotic Discharge if possible. Alternatively he casts one spell and makes one Bite Attack.

Bite. Melee Weapon Attack: +9 to hit, reach 10 ft., one creature. Hit: 12 (2d6 + 4) piercing damage, and the target must make a DC 13 Constitution saving throw, taking 30 (6d8) necrotic damage on a failed save, or half as much damage on a successful one.

Tail Swipe. Melee Weapon Attack: +9, reach 10ft., multiple creatures. Aamos moves up to 3 segments of his body by 90 degrees to his left or right. Every creature hit by his tail must succeed a DC 15 Dex Save or be pushed towards the point the Tail is pointing. Every creature it also takes 16 (4d6 + 4) Bludgeoning Damage.

Necrotic Discharge (5-6 Recharge). Melee Weapon Attack: reach 10ft., multiple creatures. Aamos sprays necrotic liquid out of his body and covers the area around him. Every creature in a 10ft radius takes 6d8 acid damage or half on a successful DC 14 Dex Save. Aamos regains the amount of damage dealt in hitpoints.

Aamos 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. Aamos regains spent legendary actions at the start of his turn.

Move. Aamos moves up to half his movement speed.

Bite. Aamos makes a Bite attack.

Command. Aamos commands up to 2 of his subjects to move up to their movement speed.

Replentish the ranks (Costs 2 Actions). Aamos raises 1d4 diseased zombie from a pile of corpses that is within a 20ft radius around him.

Cast a Spell (Costs 2 Actions). Aamos casts a spell from his list of Innate Spellcasting (if any), using a daily use as normal.