Ebbasheyth

Amphibious. Ebbasheyth can breathe air and water.

Shadow Stealth. While in dim light or darkness, Ebbasheyth can take the Hide action as a bonus action.

Sunlight Sensitivity. While in sunlight, Ebbasheyth has disadvantage on attack rolls, as well as on Wisdom (Perception) checks that rely on sight.

Living Shadow. While in dim light or darkness, Ebbasheyth has resistance to damage that isn't force, psychic, or radiant.

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

Multiattack. Ebbasheyth can use its Frightful Presence. He then makes three attacks: one with its bite and two with its claws.

Bite. Melee Weapon Attack: +11 to hit, reach 10 ft., one target. Hit: 17 (2d10 + 6) piercing damage plus 4 (1d8) necrotic damage.

Claw. Melee Weapon Attack: +11 to hit, reach 5 ft., one target. Hit: 13 (2d6 + 6) slashing damage.

Tail. Melee Weapon Attack: +11 to hit, reach 15 ft., one target. Hit: 15 (2d8 + 6) bludgeoning damage.

Frightful Presence. Each creature of Ebbasheyth's choice that is within 120 feet of the dragon and aware of it must succeed on a DC 16 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 Ebbasheyth's Frightful Presence for the next 24 hours.

Shadow Breath (Recharge 5–6). Ebbasheyth exhales acid in a 60-­foot line that is 5 feet wide. Each creature in that line must make a DC 18 Dexterity saving throw, taking 54 (12d8) necrotic damage on a failed save, or half as much damage on a successful one. A humanoid reduced to 0 hit points by this damage dies, and an undead shadow rises from its corpse and acts immediately after the draogn in the initiative count. The shadow is under Ebbasheyth's control.

Ebbasheyth 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.

Detect. Ebbasheyth makes a Wisdom (Perception) check.

Tail Attack. Ebbasheyth makes a tail attack.

Wing Attack (Costs 2 Actions). Ebbasheyth beats its wings. Each creature within 10 feet of the dragon must succeed on a DC 19 Dexterity saving throw or take 13 (2d6 + 6) bludgeoning damage and be knocked prone. Ebbasheyth can then fly up to half its flying speed.