Adult Spore Dragon

Thorny Exterior: When the Adult Spore Dragon is struck with a melee attack the attacker takes 2d4 Piercing Damage. If the melee attack is an unarmed strike, the attacker is inflicted with a bleeding effect. The Bleeding effect makes the target takes 1d6 of damage on there turn.

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

Multiattack. The Adult Spore Dragon can make one  Toxic Bite Attack, and two Claw Attacks

Frightful Presence. Each creature of the dragon'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 the dragon's Frightful Presence for the next 24 hours.

Toxic Bite. Melee Weapon Attack: + , reach 10 ft., one target. Hit: 15 (3d6 + 6) Piercing damage plus 8(2d8) Poison Damage.

Claw. Melee Weapon Attack: +11 to hit, reach 5 ft., one target. Hit: 17 (2d8 + 8) slashing damage.

Thorny Tail. Melee Weapon Attack: +9 to hit, reach 15 ft., one target. Hit: 10 (2d6 + 4) bludgeoning damage. If the tail successfully hits the target, the target is inflicted with the bleeding effect. Dealing 1d6 of damage on the start of the targets turn

Spore Breath (Recharge 5–6). The dragon exhales blast of toxic spore in a 60-foot cone. Each creature in that area must make a DC 17 Constitution saving throw, taking 54 (8d8) poison damage, and is poisoned for 1 minute on a failed save, or half as much damage on a successful one, and are not poisoned. 

Pollen Cloud: As a reaction, the Adult Spore Dragon can release a small pollen cloud from one of the blossoms on its body, to make the target reroll there attack with disadvantage.

The dragon 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. The dragon makes a Wisdom (Perception) check.

Tail Attack. The dragon makes a tail attack.

Wing Attack (Costs 2 Actions). The dragon beats its wings. Each creature within 10 feet of the dragon must succeed on a DC 17 Dexterity saving throw or take 13 (2d6 + 6) bludgeoning damage and be knocked prone. The dragon can then fly up to half its flying speed.