Wyvern

5e compatible shield

Large dragon, unaligned

Armor Class 13 (natural armor)
Hit Points 110 (13d10 + 39)
Speed 20 ft., fly 80 ft.

STR DEX CON INT WIS CHA
19 (+4) 10 (+0) 16 (+3) 5 (-3) 12 (+1) 6 (-2)

Saving Throws 
Skills Perception +4
Damage Resistances 
Damage Immunities 
Condition Immunities 
Senses darkvision 60 ft., passive Perception 14
Languages --
Challenge 6 (2300 XP)

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.