Hraesvelgr

Keen Sight (Roc Form Only). Hraesvelgr has advantage on Wisdom (Perception) checks that rely on sight.

Influence Weather. Nearby weather responds to Hraesvelgr's desires. At the start of each minute, Hraesvelgr can choose to change the precipitation and wind within 3 miles of him by one stage, up or down (no action required). This effect works like the changing weather conditions aspect of the control weather spell, except Hraesvelgr can't change the temperature and the conditions change immediately.

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

Multiattack. Hraesvelgr makes one Beak attack and two Talon attacks, or he makes three Fist attacks. Alternatively, he can make three Gale Blast attacks. If two Fist attacks hit one creature, the target must succeed on a DC 19 Constitution saving throw or be stunned until the end of its next turn.

Beak (Roc Form Only). Melee Weapon Attack: +13 to hit, reach 10 ft., one target. Hit: 25 (4d8 + 7) piercing damage.

Fist (Giant Form Only). Melee Weapon Attack: +13 to hit, reach 10 ft., one target. Hit: 20 (3d8 + 7) bludgeoning damage.

Talons (Roc Form Only). Melee Weapon Attack: +13 to hit, reach 5 ft., one target. Hit: 17 (3d6 + 7) slashing damage, and the target is grappled (escape DC 17). Until this grapple ends, the target is restrained. Hraesvelgr has two talons, each of which can grapple only one target.

Gale Blast. Ranged Spell Attack: +11 to hit, range 120 ft., one target. Hit: 14 (2d8 + 5) bludgeoning damage plus 7 (2d6) cold damage.

Swallow (Roc Form Only). Hraesvelgr makes one Beak attack against a Large or smaller creature he is grappling. If the attack hits, the target is also swallowed, and the grapple ends. While swallowed, the creature is blinded and restrained, it has total cover against attacks and other effects outside Hraesvelgr, and it takes 17 (5d6) acid damage at the start of each of Hraesvelgr's turns. Hraesvelgr can have only one creature swallowed at a time.

Sudden Gust (Recharge 5-6). Hraesvelgr unleashes a powerful gust of wind in a 60-foot line that is 10 feet wide. Each creature in the line must make a DC 19 Strength saving throw. On a failure, a creature takes 63 (18d6) bludgeoning damage and is pushed up to 15 feet away from Hraesvelgr. On a success, a creature takes half the damage and isn't pushed.

Change Shape. Hraesvelgr transforms into a roc or back into his true form, which is a Giant. His statistics, other than his speed, are the same in each form. Any equipment he is wearing or carrying isn't transformed. He reverts to his true form if he dies.

Attack. Hraesvelgr makes a Fist or Talons attack.

Move. Hraesvelgr moves up to his speed, or flies up to half his flying speed if in roc form, without provoking opportunity attacks.

Ear-Splitting Screech (Costs 2 Actions; Roc Form Only). Hraesvelgr lets out an ear-splitting screech. Each creature within 30 feet of Hraesvelgr must succeed on a DC 19 Constitution saving throw or take 14 (4d6) thunder damage and be deafened until the end of its next turn.

Attack. Hraesvelgr makes a Fist or Talons attack.

Move. Hraesvelgr moves up to his speed, or flies up to half his flying speed if in roc form, without provoking opportunity attacks.

Ear-Splitting Screech (Costs 2 Actions; Roc Form Only). Hraesvelgr lets out an ear-splitting screech. Each creature within 30 feet of Hraesvelgr must succeed on a DC 19 Constitution saving throw or take 14 (4d6) thunder damage and be deafened until the end of its next turn.