Wasteland Wyvern

Multiattack. The wyvern makes two attacks: one with its bite and one with its tail. While flying, it can use its claws in place of one other attack. It can also replace one or all of the attacks with one or two fireball attacks.

Bite. Melee Weapon Attack: +7 to hit, reach 10 ft., one creature. Hit: 16 (2d10 + 5) piercing damage plus 3 (1d6) fire damage (wyvern's choice).

Claws. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 12 (2d6 +5) slashing damage.

Headbutt. Melee Weapon Attack: +7 to hit, reach 10 ft., one creature. Hit: 11 (1d12 + 5) bludgeoning damage.

Tail. Melee Weapon Attack: +7 to hit, reach 10 ft., one creature. Hit: 11 (2d6 + 4) bludgeoning damage and the target must succeed on a DC 15 Constitution saving throw or take 1 wrath damage and be knocked prone. 

Fireball. Ranged Weapon Attack: +7 to hit, range 20/90 ft., one target. Hit: 13 (2d12) fire damage.

Cloak (Recharge 6). The wyvern casts invisibility, targeting itself.

Death Gaze (1/Day). The wyvern makes a Fireball attack on a target within range, which has advantage if the target is vulnerable to fire or necrotic damage. On a hit, the target takes no damage but must succeed on a DC 15 Constitution saving throw or, if it has 75 hit points or less, drop to 0 hit points immediately.