Wyvern

Large, dragon, unaligned

CR 6AC 13HP 110 (13d10)

Speed fly 80 ft, walk 20 ft

str: 19; (+4)
dex: 10; (+0)
con: 16; (+3)
int: 5; (-3)
wis: 12; (+1)
cha: 6; (-2)

Skills perception +4

Senses darkvision: 60 ft., passive_perception: 14

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 to hit, reach 10 ft., one creature. Hit: 11 (2d6 + 4) piercing damage.

Claws. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 13 (2d8 + 4) slashing damage.

Stinger. Melee Weapon Attack: +7 to hit, reach 10 ft., one creature. Hit: 11 (2d6 + 4) piercing damage. The target must make a DC 15 Constitution saving throw, taking 24 (7d6) poison damage on a failed save, or half as much damage on a successful one.