Medium dragon, unaligned. General description as 5e MM , but less of a threat as they are younger.
Armour class 13 (nat) Speed 20’ Fly 60’ 9D10+27 HP 77
Str 17 (+3) Dex 9 (-1) Con 13 (+1) Int 5 (-3) Wis 10 (+0) Cha 7(-2)
Perception +3
Darkvision 60’ Passive perception 11
Attacks:
Bite Melee, +5 to hit, 7’, 1D6+2 slashing.
Stinger, melee, +4 to hit, range 8’ hit D6+2 piercing. DC 10 con St. 4D6 poison dam on failed save. ½ if successful.
When flying, the wyvern can substitute a claw for one other attack
Claw, +4 to hit, reach 5’, 1D8+1 slashing dam.
Note, in a confined space, the stinger may not be effective, and the damage from claws will be reduced by 50%
Challenge 3 1000 XPs