Spellcasting Variant. A Manananggal with the Spellcasting Variant is CR 4, and its Charisma Ability score is increased to 16. The Manananggal's innate Spellcasting ability is Charisma (Spell Save DC 13), and it can cast the following spells, not requiring material components:

Blood Sense. The Manananggal knows the distance and direction of any enemy that doesn't have all its hit points, within 240 feet of it.   Severance. During the day, the Manananggal appears identical to a living humanoid, and does not register as undead to magical effects despite being an undead creature. At nightfall, the Manananggal must take its turn to change into its true form, at which point bat-like wings erupt from its back, sharp predatory teeth sprout from its mouth, and its torso brutally tears from its lower body. Its statistics, other than its movement speed, are the same in each form. Its lower torso remains standing upright, unmoving until its reconnects with its upper body, or until the upper body is killed. Its upper and lower torso share the same pool of hit points, and if the lower portion is damaged, then the upper portion is immediately aware of the attack. It takes a full turn for the two halves to reconnect. Holy water, ash, or silver dust can be smeared or sprinkled thoroughly on top of the standing lower torso to prevent the two halves from reconnecting ever again.   Sunlight Hypersensitivity. If the Manananggal has not reattached to its lower body by sunrise, it takes 15 radiant damage when it starts its turn in sunlight, and has disadvantage on Attack rolls and Ability Checks while in sunlight.   Undead Fortitude. If damage reduces the Manananggal to 0 hit points, it must make a Constitution saving throw equal to 5 plus the damage taken, unless the damage is from a silvered weapon, radiant, or a critical hit. On a success, the Manananggal drops to 1 hit point instead.