The body was cut down under a sickly noontime sun, and all through the day, and into the night the worker of dark arts performed his foul ritual. As the new day dawned a ghastly abomination shakily rose up. It's sickly legs wobbled like a newly fowled calf, and it's sightless eyes looked around in malevolent astonishment. With not a word, it's creator sent it forth to terrorize the villagers in death as he had in life.
Large undead, chaotic evil
Armor Class 13 (natural armor)
Hit Points 58 (9d8+18)
Speed 40 ft.
Damage Immunities necrotic, poison
Damage Resistances piercing from non-magical weapons, psychic
Condition Immunities charmed, exhaustion, frightened, poisoned, unconscious
Senses Darkvision 60 ft., passive Perception 10
Languages understands all languages it knew in life but can’t speak
Challenge 3 (700XP)
Multiattack. The gallowgaunt makes two attacks: one with it’s chains and one with it’s blades
Chains. Melee Weapon Attack: +5 to hit, reach 10 ft., one target. Hit 10: (2d6+3) bludgeoning damage, and target creature must make a DC 15 Dexterity Saving Throw or be Restrained.
Blades. Melee Weapon Attack: +5 to hit, reach 10 ft., one target. Hit 10: (2d6+3) slashing damage.
Death Clatter. All non-undead non-deafened creatures within 30 feet of the gallowgaunt must succeed on a DC 12 Wisdom Saving Throw or gain a level of exhaustion.
Scream of the Damned (1/Day): All non-undead non-deafened creatures within 30’ of the gallowsgaunt must make a DC 13 Constitution saving throw, taking 13 (3d8) psychic damage on a failed save, or half as much on a successful one.
This revisits the GallowsGaunt I'd written up back in the early days of my blog for both Rules Cyclopedia, M20, and 4e.