Battra

Legendary Resistance (3/Day). If Battra fails a saving throw, it can choose to succeed instead.

Magic Resistance. Battra has advantage on saving throws against spells and other magical effects.

Primal Strikes. Battra ignores other creatures' resistance and immunity to non-magical bludgeoning, piercing, and slashing damage.

Siege Monster. Battra deals double damage to objects and structures.

Trample. When Battra enters any enemy's space for the first time on a turn, the enemy must succeed on a DC 22 Strength saving throw or be knocked prone.

Antennae. Battra has advantage on Wisdom (Perception) checks that rely on smell.

Spell Reflection. When a creature targets Battra with a spell attack and misses, or it succeeds on its saving throw against a spell or other magical effect, the effect is reflected back at the caster as though it originated from the Battra, turning the caster into the target.

Multi-attack. Battra can use its Frightful Presence. Then it makes four bite attacks.

Frightful Presence. Each creature of Battra's choice that is within 120 feet of it and aware of it must succeed on a DC 15 Wisdom saving throw or become frightened for 1 minute. A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. If a creature's saving throw is successful or the effect ends for it, the creature is immune to Battra's Frightful Presence for the next 24 hours.

Bite. Melee Weapon Attack: +14 to hit, reach 15 ft., one target. Hit: 21 (4d6 + 7) piercing damage.

Powdery Wings (1/day). A 30-foot radius cloud of fine powder disperses from Battra. Each creature in that area must succeed on a DC 19 Constitution saving throw or be blinded until the end of its next turn.

Windstorm. As an action, Battra blasts an area with powerful gusts of wind by flapping its wings. Until the start of its next turn, creatures and objects within a 100-foot cone are affected as they would be by the gust of wind spell. The save DC for this effect equals 19.

Battra can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another creature's turn. Battra regains spent legendary actions at the start of its turn.

Detect. Battra makes a Wisdom (Perception) check.
Move. Battra flies up to half its speed.
Attack. Battra makes one bite attack.

Wing Attack (Costs 2 Actions). Battra beats its wings. Each creature within 15 ft. of it must succeed on a DC 22 Dexterity saving throw or take bludgeoning damage equal to 2d6 + 7 and be knocked prone. Battra can then fly up to half its flying speed.