Armor Class 17 (natural armor)
Hit Points 91 (14d8 + 28)
Speed 30 ft.
Saving Throws WIS +4
Skills Nature +4, Perception +4, Stealth +6, Survival +4
Damage Immunities cold
Senses darkvision 60 ft., passive Perception 14
Languages Auran, Common, Giant
Challenge 7
Graystaff Magic. The hag carries a graystaff, a length of gray wood that is a focus for her inner power. She can ride the staff as if it were a broom of flying. While holding the staff, she can cast additional spells with her Innate Spellcasting trait (these spells are marked with an asterisk). If the staff is lost or destroyed, the hag must craft another, which takes a year and a day. Only a bheur hag can use a graystaff.
Ice Walk. The hag can move across and climb icy surfaces without needing to make an ability check. Additionally, 3 composed of ice or snow doesn't cost her extra moment.
Slam. Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: 10 (2d8 + 1) bludgeoning damage plus 3 (1d6) cold damage.
Maddening Feast. The hag feasts on the corpse of one enemy within 5 feet of her that died within the past minute. Each creature of the hag's choice that is within 60 feet of her and able to see her must succeed on a DC 15 Wisdom saving throw or be frightened of her for 1 minute. While frightened in this way, a creature is incapacitated, can't understand what others say, can't read, and speaks only in gibberish; the DM controls the creature's movement, which is erratic. 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 the hag's Maddening Feast for the next 24 hours.
Volo's Guide to Monsters, p. 160