Uthwix, The Broodmother

Legendary Resistance 3/day. If the dragon fails a saving throw it can choose to succeed instead.

Brood. At the beginning of the fight Uthwix has 15 pseudo dragons around her.

Secreting Oil. Uthwix has a thin layer of oil seeping out of her scales. This oil gives any grapple or physical restraints disadvantage.

Weak Skin. Uthwix has hundreds of eggs currently waiting inside of her skin. whenever she suffers more than 25 hit points of damage from a single attack an egg hatches adding one pseudo dragon to her horde.

Pseudo Dragons. The pseudo dragons around Uthwix are newly born and very weak. Each one only has 1 hit point, but if they save from an area of effect spell they take zero damage instead of half.

Multi-Attack. Uthwix makes two claw attacks, then a bite attack, then an egg attack.

Bite. Melee Weapon Attack: +16 to hit, reach 15 ft., one target. Hit: 20 (2d10 + 9) piercing damage plus 11 (2d10) Acid damage.

Claw. Melee Weapon Attack: +16 to hit, reach 10 ft., one target. Hit: 16 (2d6 + 9) slashing damage.

Egg. Ranged Weapon Attack: +16 to hit, range 20/60 ft., 1 target. Hit:  11 (1d4 + 9) piercing damage. The target rolls a CON save or has the egg embed itself inside of the creature. The egg stays dormant inside the creature either until Uthwix causes it to awaken or eight hours after the egg attack.

Command the horde (Recharge 5-6). The dragon issues a command of attack in a 60ft cone in front of her. The horde of pseudo dragons attack all creatures in that area. Creatures in that area roll a DC 20 DEX save or take 1d4 piercing and 1d4 bludgeoning damage per pseudo dragon currently spawned.

Burst. Whenever a creature makes a melee attack on Uthwix she can use her reaction to cause a an egg in her skin to burst and shoot acid at the attacker. The attacker makes a CON save or takes 2d4 acid damage, halved for a success.

Uthwix 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. Uthwix regains spent legendary actions at the start of its turn.

Detect (Costs 1 Actions). The dragon makes a Wisdom (Perception) check.

Tail Attack (Costs 1 Actions). The dragon makes a tail attack.

Breed (Costs 2 Actions). The dragon breeds out four pseudo dragons that join her flying horde.