Large dragon, unaligned

Armor Class: 14

Hit Points: 119 (14d10+42) 14d10+42

Speed: 20 ft , fly: 80 ft

STR

18 +4

DEX

12 +1

CON

16 +3

INT

6 -2

WIS

13 +1

CHA

4 -3

Skills: Perception +7 1d20+7

Senses: Blindsight 30 ft., Darkvision 60 ft., passive perception 17

Challenge Rating: 7

Actions

Multiattack: The wyvern makes two attacks: one with its bite and one with its Stinger. While flying, it can use its claws in place of one other Attack.   Bite. Melee Weapon Attack: +7 1d20+7 to hit, reach 10 ft., one creature. Hit: 11 (2d6 + 4) 2d6+4 piercing damage.   Claws. Melee Weapon Attack: +7 1d20+7 to hit, reach 5 ft., one target. Hit: 13 (2d8 + 4) 2d8+4 slashing damage. The target must make a DC 15 Constitution saving throw, taking 14 (4d6) 4d6 poison damage and have their Strength score reduced by 1d4 1d4 on a failed save, or half take half as much damage and not have their Strength reduced on a successful one. The Strength reduction lasts until the creature has completed a long rest.   Stinger. Melee Weapon Attack: +7 1d20+7 to hit, reach 10 ft., one creature. Hit: 11 (2d6 + 4) 2d6+4 piercing damage. If the target is a Medium or smaller creature, it is Grappled (escape DC 17). Until this grapple ends, the target is Restrained, and the wyvern can’t use its stinger.