Acidic Blood. Any nonmagical weapon made of metal that hits the Xeno Dragon corrodes. After dealing damage, the weapon takes a permanent and cumulative -1 penalty to  damage rolls. If its penalty drops to -5, the weapon is destroyed. Nonmagical ammunition made of metal that hits the Xeno Dragon is destroyed after dealing damage. Whenever the Xeno Dragon takes physical damage, any other creature within 5 feet of it must succeed on a DC 15 Dexterity saving throw or take 5 (1d8) acid damage

Hive Mind. The Xeno Dragon are mentally linked to their respective Queen.

Spider Climb. The Xeno Dragon can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check.

Night Stalker. The Xeno Dragon has advantage on stealth rolls in dim lighting and total darkness.

Legendary Resistance (3/day).  If the Xeno Dragon fails a saving throw, it can choose to succeed instead.

Multiattack. The Xeno Dragon can use its Frightful Presence. It then makes three attacks: one with its Bite and two with its Claw attacks.

Claw. Melee Weapon Attack: +16 to hit, reach 10 ft., one. Hit: 22 (3d8+10) slashing damage

Bite. Melee Weapon Attack: +16 to hit, reach 15ft., one. Hit: 39 (8d6+10) piercing damage. and 32 (8d6) acid damage.

Tail Slash. Melee Weapon Attack: +16 to hit, reach 20 ft., one. Hit: 49 (7d10+8) slashing damage.

Acid Breath (Recharge 5-6}. The Xeno Dragon exhales  acid in a 120-foot line, 10 feet wide. Each creature in that area must make a DC 23 DEX saving throw, taking 88 (16d10) acid 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, the acid leaving no body left behind.

Freighting Presence. The Xeno Dragon shrieks. Each creature of her choice that is within 120ft of her must succeed on a DC 20 WIS saving throw or become frightened for 1 minute. The creature can repeat the savings throw at the end of each of its turns. Once a creature has successfully passed the saving throw it is immune to the Xeno Dragon Freighting Presence for the next 24 hours.

The Xeno Dragon can take 3 legendary actions, choosing from the options below. Only one legendary action can be used at a time and only at the end of another creature's turn. The Xeno Dragon regains spent legendary actions at the start of its turn.

Claw. 1 Action.

Tail Slash. 1 Action. The Xeno Dragon makes one Tail Slash attack. On a hit the target must make a DC 20 DEX saving throw or be knocked prone.

Wing Attack. 2 Actions. The Xeno Dragon beats its wings. Each creature within 15ft of the dragon must succeed on a DC 24 DEX or STR saving throw or take 17 (2d6 + 10) bludgeoning damage and be knocked prone. The Xeno Dragon can then fly up to half its flying speed.