Ancient Flying Tortoise (Obojima)

Flying. Creature is capable of flying both by itself and as a mount.

Spellcasting. The tortoise is a 5-level spellcaster. Its spellcasting ability is Wisdom (spell save DC 8, +6 to hit with spell attacks). The tortoise has following Druid spells prepared:
Cantrips (at will): Guidance, Resistance, Starry Whisp
1st level (4 slots): Sand Structure, Healing Word, Water Bullet
2nd level (3 slots): Pillar of Force, Spell Signature, Moonbeam
3rd level (2 slots): Revivify, Protection from Energy, Dispel Magic

Cannot use magic actions while mounted.

Bite. Melee Weapon Attack: +5 to hit, reach 10 ft., one target. Hit: 11 (1d12 + 3) piercing damage.

Steam Breath (Recharge 5–6). The ancient tortoise exhales steam in a 15-foot cone. Each creature in that area must make a DC 12 Constitution saving throw, taking 17 (5d6) fire damage on a failed save, or half as much damage on a successful one. Being underwater doesn't grant resistance against this damage.

Shell Spinning (Recharge 4-6). The ancient tortoise retracts into its shell and spins 30ft in any direction, ignoring difficult terrain and not prompting opportunity attacks. Any creature that stands between [monster name] and its destination must make a DC 14 Dexterity save or take 3d6 bludgeoning damage.

Enter Shell. Temporarily raises AC to 22